<!--
Documentation of the system catalogs, directed toward PostgreSQL developers
- $Header: /cvsroot/pgsql/doc/src/sgml/catalogs.sgml,v 2.68 2003/03/25 16:15:35 petere Exp $
+ $Header: /cvsroot/pgsql/doc/src/sgml/catalogs.sgml,v 2.69 2003/04/15 13:23:35 petere Exp $
-->
<chapter id="catalogs">
<title>System Catalogs</title>
- <sect1 id="catalogs-overview">
- <title>Overview</title>
-
<para>
The system catalogs are the place where a relational database
management system stores schema metadata, such as information about
<productname>PostgreSQL</productname>'s system catalogs are regular
tables. You can drop and recreate the tables, add columns, insert
and update values, and severely mess up your system that way.
- Normally one should not change the system catalogs by hand, there
+ Normally, one should not change the system catalogs by hand, there
are always SQL commands to do that. (For example, <command>CREATE
DATABASE</command> inserts a row into the
- <structname>pg_database</structname> catalog -- and actually
+ <structname>pg_database</structname> catalog --- and actually
creates the database on disk.) There are some exceptions for
- especially esoteric operations, such as adding index access methods.
+ particularly esoteric operations, such as adding index access methods.
+ </para>
+
+ <sect1 id="catalogs-overview">
+ <title>Overview</title>
+
+ <para>
+ <xref linkend="catalog-table"> lists the system catalogs.
+ More detailed documentation of each catalog follows below.
</para>
+
<para>
Most system catalogs are copied from the template database during
- database creation, and are thereafter database-specific. A few
- catalogs are physically shared across all databases in an installation;
+ database creation and are thereafter database-specific. A few
+ catalogs are physically shared across all databases in a cluster;
these are marked in the descriptions of the individual catalogs.
</para>
- <table>
+ <table id="catalog-table">
<title>System Catalogs</title>
<tgroup cols="2">
<tbody>
<row>
- <entry><link linkend="catalog-pg-aggregate">
- <database class="table">pg_aggregate</database></link></entry>
+ <entry><link linkend="catalog-pg-aggregate"><structname>pg_aggregate</structname></link></entry>
<entry>aggregate functions</entry>
</row>
<row>
- <entry>pg_am</entry>
+ <entry><link linkend="catalog-pg-am"><structname>pg_am</structname></link></entry>
<entry>index access methods</entry>
</row>
<row>
- <entry>pg_amop</entry>
+ <entry><link linkend="catalog-pg-amop"><structname>pg_amop</structname></link></entry>
<entry>access method operators</entry>
</row>
<row>
- <entry>pg_amproc</entry>
+ <entry><link linkend="catalog-pg-amproc"><structname>pg_amproc</structname></link></entry>
<entry>access method support procedures</entry>
</row>
<row>
- <entry><link linkend="catalog-pg-attrdef">
- <database class="table">pg_attrdef</database></link></entry>
+ <entry><link linkend="catalog-pg-attrdef"><structname>pg_attrdef</structname></link></entry>
<entry>column default values</entry>
</row>
<row>
- <entry><link linkend="catalog-pg-attribute">
- <database class="table">pg_attribute</database></link></entry>
- <entry>table columns (<quote>attributes</quote>, <quote>fields</quote>)</entry>
+ <entry><link linkend="catalog-pg-attribute"><structname>pg_attribute</structname></link></entry>
+ <entry>table columns (<quote>attributes</quote>)</entry>
</row>
<row>
- <entry><link linkend="catalog-pg-cast">
- <database class="table">pg_cast</database></link></entry>
+ <entry><link linkend="catalog-pg-cast"><structname>pg_cast</structname></link></entry>
<entry>casts (data type conversions)</entry>
</row>
<row>
- <entry><link linkend="catalog-pg-class">
- <database class="table">pg_class</database></link></entry>
+ <entry><link linkend="catalog-pg-class"><structname>pg_class</structname></link></entry>
<entry>tables, indexes, sequences (<quote>relations</quote>)</entry>
</row>
<row>
- <entry><link linkend="catalog-pg-constraint">
- <database class="table">pg_constraint</database></link></entry>
- <entry>check constraints, unique / primary key constraints, foreign key constraints</entry>
+ <entry><link linkend="catalog-pg-constraint"><structname>pg_constraint</structname></link></entry>
+ <entry>check constraints, unique constraints, primary key constraints, foreign key constraints</entry>
</row>
<row>
- <entry><link linkend="catalog-pg-conversion">
- <database class="table">pg_conversion</database></link></entry>
+ <entry><link linkend="catalog-pg-conversion"><structname>pg_conversion</structname></link></entry>
<entry>encoding conversion information</entry>
</row>
<row>
- <entry><link linkend="catalog-pg-database">
- <database class="table">pg_database</database></link></entry>
+ <entry><link linkend="catalog-pg-database"><structname>pg_database</structname></link></entry>
<entry>databases within this database cluster</entry>
</row>
<row>
- <entry><link linkend="catalog-pg-depend">
- <database class="table">pg_depend</database></link></entry>
+ <entry><link linkend="catalog-pg-depend"><structname>pg_depend</structname></link></entry>
<entry>dependencies between database objects</entry>
</row>
<row>
- <entry><link linkend="catalog-pg-description">
- <database class="table">pg_description</database></link></entry>
+ <entry><link linkend="catalog-pg-description"><structname>pg_description</structname></link></entry>
<entry>descriptions or comments on database objects</entry>
</row>
<row>
- <entry><link linkend="catalog-pg-group">
- <database class="table">pg_group</database></link></entry>
+ <entry><link linkend="catalog-pg-group"><structname>pg_group</structname></link></entry>
<entry>groups of database users</entry>
</row>
<row>
- <entry><link linkend="catalog-pg-index">
- <database class="table">pg_index</database></link></entry>
+ <entry><link linkend="catalog-pg-index"><structname>pg_index</structname></link></entry>
<entry>additional index information</entry>
</row>
<row>
- <entry><link linkend="catalog-pg-inherits">
- <database class="table">pg_inherits</database></link></entry>
+ <entry><link linkend="catalog-pg-inherits"><structname>pg_inherits</structname></link></entry>
<entry>table inheritance hierarchy</entry>
</row>
<row>
- <entry><link linkend="catalog-pg-language">
- <database class="table">pg_language</database></link></entry>
+ <entry><link linkend="catalog-pg-language"><structname>pg_language</structname></link></entry>
<entry>languages for writing functions</entry>
</row>
<row>
- <entry><link linkend="catalog-pg-largeobject">
- <database class="table">pg_largeobject</database></link></entry>
+ <entry><link linkend="catalog-pg-largeobject"><structname>pg_largeobject</structname></link></entry>
<entry>large objects</entry>
</row>
<row>
- <entry><link linkend="catalog-pg-listener">
- <database class="table">pg_listener</database></link></entry>
- <entry>asynchronous notification</entry>
+ <entry><link linkend="catalog-pg-listener"><structname>pg_listener</structname></link></entry>
+ <entry>asynchronous notification support</entry>
</row>
<row>
- <entry><link linkend="catalog-pg-namespace">
- <database class="table">pg_namespace</database></link></entry>
- <entry>namespaces (schemas)</entry>
+ <entry><link linkend="catalog-pg-namespace"><structname>pg_namespace</structname></link></entry>
+ <entry>schemas</entry>
</row>
<row>
- <entry><link linkend="catalog-pg-opclass">
- <database class="table">pg_opclass</database></link></entry>
+ <entry><link linkend="catalog-pg-opclass"><structname>pg_opclass</structname></link></entry>
<entry>index access method operator classes</entry>
</row>
<row>
- <entry><link linkend="catalog-pg-operator">
- <database class="table">pg_operator</database></link></entry>
+ <entry><link linkend="catalog-pg-operator"><structname>pg_operator</structname></link></entry>
<entry>operators</entry>
</row>
<row>
- <entry><link linkend="catalog-pg-proc">
- <database class="table">pg_proc</database></link></entry>
+ <entry><link linkend="catalog-pg-proc"><structname>pg_proc</structname></link></entry>
<entry>functions and procedures</entry>
</row>
<row>
- <entry><link linkend="catalog-pg-rewrite">
- <database class="table">pg_rewrite</database></link></entry>
- <entry>query rewriter rules</entry>
+ <entry><link linkend="catalog-pg-rewrite"><structname>pg_rewrite</structname></link></entry>
+ <entry>query rewrite rules</entry>
</row>
<row>
- <entry><link linkend="catalog-pg-shadow">
- <database class="table">pg_shadow</database></link></entry>
+ <entry><link linkend="catalog-pg-shadow"><structname>pg_shadow</structname></link></entry>
<entry>database users</entry>
</row>
<row>
- <entry><link linkend="catalog-pg-statistic">
- <database class="table">pg_statistic</database></link></entry>
- <entry>optimizer statistics</entry>
+ <entry><link linkend="catalog-pg-statistic"><structname>pg_statistic</structname></link></entry>
+ <entry>planner statistics</entry>
</row>
<row>
- <entry><link linkend="catalog-pg-trigger">
- <database class="table">pg_trigger</database></link></entry>
+ <entry><link linkend="catalog-pg-trigger"><structname>pg_trigger</structname></link></entry>
<entry>triggers</entry>
</row>
<row>
- <entry><link linkend="catalog-pg-type">
- <database class="table">pg_type</database></link></entry>
+ <entry><link linkend="catalog-pg-type"><structname>pg_type</structname></link></entry>
<entry>data types</entry>
</row>
</tbody>
</tgroup>
</table>
-
- <para>
- More detailed documentation of each catalog follows below.
- </para>
-
</sect1>
<sect1 id="catalog-pg-aggregate">
- <title>pg_aggregate</title>
+ <title><structname>pg_aggregate</structname></title>
+
+ <indexterm zone="catalog-pg-aggregate">
+ <primary>pg_aggregate</primary>
+ </indexterm>
<para>
- <structname>pg_aggregate</structname> stores information about
+ The catalog <structname>pg_aggregate</structname> stores information about
aggregate functions. An aggregate function is a function that
operates on a set of values (typically one column from each row
that matches a query condition) and returns a single value computed
<function>max</function>. Each entry in
<structname>pg_aggregate</structname> is an extension of an entry
in <structname>pg_proc</structname>. The <structname>pg_proc</structname>
- entry carries the aggregate's name, input and output datatypes, and
+ entry carries the aggregate's name, input and output data types, and
other information that is similar to ordinary functions.
</para>
<table>
- <title>pg_aggregate Columns</title>
+ <title><structname>pg_aggregate</> Columns</title>
<tgroup cols=4>
<thead>
</thead>
<tbody>
<row>
- <entry>aggfnoid</entry>
+ <entry><structfield>aggfnoid</structfield></entry>
<entry><type>regproc</type></entry>
- <entry>pg_proc.oid</entry>
- <entry>pg_proc OID of the aggregate function</entry>
+ <entry><literal>pg_proc.oid</literal></entry>
+ <entry><structname>pg_proc</structname> OID of the aggregate function</entry>
</row>
<row>
- <entry>aggtransfn</entry>
+ <entry><structfield>aggtransfn</structfield></entry>
<entry><type>regproc</type></entry>
- <entry>pg_proc.oid</entry>
+ <entry><literal>pg_proc.oid</literal></entry>
<entry>Transition function</entry>
</row>
<row>
- <entry>aggfinalfn</entry>
+ <entry><structfield>aggfinalfn</structfield></entry>
<entry><type>regproc</type></entry>
- <entry>pg_proc.oid</entry>
+ <entry><literal>pg_proc.oid</literal></entry>
<entry>Final function (zero if none)</entry>
</row>
<row>
- <entry>aggtranstype</entry>
+ <entry><structfield>aggtranstype</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_type.oid</entry>
+ <entry><literal>pg_type.oid</literal></entry>
<entry>The type of the aggregate function's internal transition (state) data</entry>
</row>
<row>
- <entry>agginitval</entry>
+ <entry><structfield>agginitval</structfield></entry>
<entry><type>text</type></entry>
<entry></entry>
<entry>
The initial value of the transition state. This is a text
field containing the initial value in its external string
- representation. If the field is NULL, the transition state
- value starts out NULL.
+ representation. If the value is null, the transition state
+ value starts out null.
</entry>
</row>
</tbody>
<sect1 id="catalog-pg-am">
- <title>pg_am</title>
+ <title><structname>pg_am</structname></title>
+
+ <indexterm zone="catalog-pg-am">
+ <primary>pg_am</primary>
+ </indexterm>
<para>
- <structname>pg_am</structname> stores information about index access
+ The catalog <structname>pg_am</structname> stores information about index access
methods. There is one row for each index access method supported by
the system.
</para>
<table>
- <title>pg_am Columns</title>
+ <title><structname>pg_am</> Columns</title>
<tgroup cols=4>
<thead>
<tbody>
<row>
- <entry>amname</entry>
+ <entry><structfield>amname</structfield></entry>
<entry><type>name</type></entry>
<entry></entry>
- <entry>name of the access method</entry>
+ <entry>Name of the access method</entry>
</row>
<row>
- <entry>amowner</entry>
+ <entry><structfield>amowner</structfield></entry>
<entry><type>int4</type></entry>
- <entry>pg_shadow.usesysid</entry>
- <entry>user ID of the owner (currently not used)</entry>
+ <entry><literal>pg_shadow.usesysid</literal></entry>
+ <entry>User ID of the owner (currently not used)</entry>
</row>
<row>
- <entry>amstrategies</entry>
+ <entry><structfield>amstrategies</structfield></entry>
<entry><type>int2</type></entry>
<entry></entry>
- <entry>number of operator strategies for this access method</entry>
+ <entry>Number of operator strategies for this access method</entry>
</row>
<row>
- <entry>amsupport</entry>
+ <entry><structfield>amsupport</structfield></entry>
<entry><type>int2</type></entry>
<entry></entry>
- <entry>number of support routines for this access method</entry>
+ <entry>Number of support routines for this access method</entry>
</row>
<row>
- <entry>amorderstrategy</entry>
+ <entry><structfield>amorderstrategy</structfield></entry>
<entry><type>int2</type></entry>
<entry></entry>
- <entry>zero if the index offers no sort order, otherwise the strategy
+ <entry>Zero if the index offers no sort order, otherwise the strategy
number of the strategy operator that describes the sort order</entry>
</row>
<row>
- <entry>amcanunique</entry>
+ <entry><structfield>amcanunique</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
- <entry>does AM support unique indexes?</entry>
+ <entry>Does the access method support unique indexes?</entry>
</row>
<row>
- <entry>amcanmulticol</entry>
+ <entry><structfield>amcanmulticol</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
- <entry>does AM support multicolumn indexes?</entry>
+ <entry>Does the access method support multicolumn indexes?</entry>
</row>
<row>
- <entry>amindexnulls</entry>
+ <entry><structfield>amindexnulls</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
- <entry>does AM support NULL index entries?</entry>
+ <entry>Does the access method support null index entries?</entry>
</row>
<row>
- <entry>amconcurrent</entry>
+ <entry><structfield>amconcurrent</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
- <entry>does AM support concurrent updates?</entry>
+ <entry>Does the access method support concurrent updates?</entry>
</row>
<row>
- <entry>amgettuple</entry>
+ <entry><structfield>amgettuple</structfield></entry>
<entry><type>regproc</type></entry>
- <entry>pg_proc.oid</entry>
- <entry><quote>next valid tuple</quote> function</entry>
+ <entry><literal>pg_proc.oid</literal></entry>
+ <entry><quote>Next valid tuple</quote> function</entry>
</row>
<row>
- <entry>aminsert</entry>
+ <entry><structfield>aminsert</structfield></entry>
<entry><type>regproc</type></entry>
- <entry>pg_proc.oid</entry>
- <entry><quote>insert this tuple</quote> function</entry>
+ <entry><literal>pg_proc.oid</literal></entry>
+ <entry><quote>Insert this tuple</quote> function</entry>
</row>
<row>
- <entry>ambeginscan</entry>
+ <entry><structfield>ambeginscan</structfield></entry>
<entry><type>regproc</type></entry>
- <entry>pg_proc.oid</entry>
- <entry><quote>start new scan</quote> function</entry>
+ <entry><literal>pg_proc.oid</literal></entry>
+ <entry><quote>Start new scan</quote> function</entry>
</row>
<row>
- <entry>amrescan</entry>
+ <entry><structfield>amrescan</structfield></entry>
<entry><type>regproc</type></entry>
- <entry>pg_proc.oid</entry>
- <entry><quote>restart this scan</quote> function</entry>
+ <entry><literal>pg_proc.oid</literal></entry>
+ <entry><quote>Restart this scan</quote> function</entry>
</row>
<row>
- <entry>amendscan</entry>
+ <entry><structfield>amendscan</structfield></entry>
<entry><type>regproc</type></entry>
- <entry>pg_proc.oid</entry>
- <entry><quote>end this scan</quote> function</entry>
+ <entry><literal>pg_proc.oid</literal></entry>
+ <entry><quote>End this scan</quote> function</entry>
</row>
<row>
- <entry>ammarkpos</entry>
+ <entry><structfield>ammarkpos</structfield></entry>
<entry><type>regproc</type></entry>
- <entry>pg_proc.oid</entry>
- <entry><quote>mark current scan position</quote> function</entry>
+ <entry><literal>pg_proc.oid</literal></entry>
+ <entry><quote>Mark current scan position</quote> function</entry>
</row>
<row>
- <entry>amrestrpos</entry>
+ <entry><structfield>amrestrpos</structfield></entry>
<entry><type>regproc</type></entry>
- <entry>pg_proc.oid</entry>
- <entry><quote>restore marked scan position</quote> function</entry>
+ <entry><literal>pg_proc.oid</literal></entry>
+ <entry><quote>Restore marked scan position</quote> function</entry>
</row>
<row>
- <entry>ambuild</entry>
+ <entry><structfield>ambuild</structfield></entry>
<entry><type>regproc</type></entry>
- <entry>pg_proc.oid</entry>
- <entry><quote>build new index</quote> function</entry>
+ <entry><literal>pg_proc.oid</literal></entry>
+ <entry><quote>Build new index</quote> function</entry>
</row>
<row>
- <entry>ambulkdelete</entry>
+ <entry><structfield>ambulkdelete</structfield></entry>
<entry><type>regproc</type></entry>
- <entry>pg_proc.oid</entry>
- <entry>bulk-delete function</entry>
+ <entry><literal>pg_proc.oid</literal></entry>
+ <entry>Bulk-delete function</entry>
</row>
<row>
- <entry>amvacuumcleanup</entry>
+ <entry><structfield>amvacuumcleanup</structfield></entry>
<entry><type>regproc</type></entry>
- <entry>pg_proc.oid</entry>
- <entry>post-VACUUM cleanup function</entry>
+ <entry><literal>pg_proc.oid</literal></entry>
+ <entry>Post-<command>VACUUM</command> cleanup function</entry>
</row>
<row>
- <entry>amcostestimate</entry>
+ <entry><structfield>amcostestimate</structfield></entry>
<entry><type>regproc</type></entry>
- <entry>pg_proc.oid</entry>
- <entry>estimate cost of an indexscan</entry>
+ <entry><literal>pg_proc.oid</literal></entry>
+ <entry>Function to estimate cost of an index scan</entry>
</row>
</tbody>
</table>
<para>
- An index AM that supports multiple columns (has
+ An index access method that supports multiple columns (has
<structfield>amcanmulticol</structfield> true) <emphasis>must</>
- support indexing nulls in columns after the first, because the planner
+ support indexing null values in columns after the first, because the planner
will assume the index can be used for queries on just the first
- column(s). For example, consider an index on (a,b) and a query
- WHERE a = 4. The system will assume the index can be used to scan for
- rows with a = 4, which is wrong if the index omits rows where b is null.
- However it is okay to omit rows where the first indexed column is null.
+ column(s). For example, consider an index on (a,b) and a query with
+ <literal>WHERE a = 4</literal>. The system will assume the index can be used to scan for
+ rows with <literal>a = 4</literal>, which is wrong if the index omits rows where <literal>b</> is null.
+ It is, however, OK to omit rows where the first indexed column is null.
(GiST currently does so.)
<structfield>amindexnulls</structfield> should be set true only if the
- index AM indexes all rows, including arbitrary combinations of nulls.
+ index access method indexes all rows, including arbitrary combinations of null values.
</para>
</sect1>
<sect1 id="catalog-pg-amop">
- <title>pg_amop</title>
+ <title><structname>pg_amop</structname></title>
+
+ <indexterm zone="catalog-pg-amop">
+ <primary>pg_amop</primary>
+ </indexterm>
<para>
- <structname>pg_amop</structname> stores information about operators
+ The catalog <structname>pg_amop</structname> stores information about operators
associated with index access method operator classes. There is one
row for each operator that is a member of an operator class.
</para>
<table>
- <title>pg_amop Columns</title>
+ <title><structname>pg_amop</> Columns</title>
<tgroup cols=4>
<thead>
<tbody>
<row>
- <entry>amopclaid</entry>
+ <entry><structfield>amopclaid</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_opclass.oid</entry>
- <entry>the index opclass this entry is for</entry>
+ <entry><literal>pg_opclass.oid</literal></entry>
+ <entry>The index operator class this entry is for</entry>
</row>
<row>
- <entry>amopstrategy</entry>
+ <entry><structfield>amopstrategy</structfield></entry>
<entry><type>int2</type></entry>
<entry></entry>
- <entry>operator strategy number</entry>
+ <entry>Operator strategy number</entry>
</row>
<row>
- <entry>amopreqcheck</entry>
+ <entry><structfield>amopreqcheck</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
- <entry>index hit must be rechecked</entry>
+ <entry>Index hit must be rechecked</entry>
</row>
<row>
- <entry>amopopr</entry>
+ <entry><structfield>amopopr</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_operator.oid</entry>
- <entry>the operator's pg_operator OID</entry>
+ <entry><literal>pg_operator.oid</literal></entry>
+ <entry>OID of the operator</entry>
</row>
</tbody>
<sect1 id="catalog-pg-amproc">
- <title>pg_amproc</title>
+ <title><structname>pg_amproc</structname></title>
+
+ <indexterm zone="catalog-pg-amproc">
+ <primary>pg_amproc</primary>
+ </indexterm>
<para>
- <structname>pg_amproc</structname> stores information about support
+ The catalog <structname>pg_amproc</structname> stores information about support
procedures
associated with index access method operator classes. There is one
row for each support procedure belonging to an operator class.
</para>
<table>
- <title>pg_amproc Columns</title>
+ <title><structname>pg_amproc</structname> Columns</title>
<tgroup cols=4>
<thead>
<tbody>
<row>
- <entry>amopclaid</entry>
+ <entry><structfield>amopclaid</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_opclass.oid</entry>
- <entry>the index opclass this entry is for</entry>
+ <entry><literal>pg_opclass.oid</literal></entry>
+ <entry>The index operator class this entry is for</entry>
</row>
<row>
- <entry>amprocnum</entry>
+ <entry><structfield>amprocnum</structfield></entry>
<entry><type>int2</type></entry>
<entry></entry>
- <entry>support procedure index</entry>
+ <entry>Support procedure number</entry>
</row>
<row>
- <entry>amproc</entry>
+ <entry><structfield>amproc</structfield></entry>
<entry><type>regproc</type></entry>
- <entry>pg_proc.oid</entry>
- <entry>OID of the proc</entry>
+ <entry><literal>pg_proc.oid</literal></entry>
+ <entry>OID of the procedure</entry>
</row>
</tbody>
<sect1 id="catalog-pg-attrdef">
- <title>pg_attrdef</title>
+ <title><structname>pg_attrdef</structname></title>
+
+ <indexterm zone="catalog-pg-attrdef">
+ <primary>pg_attrdef</primary>
+ </indexterm>
<para>
- This catalog stores column default values. The main information
+ The catalog <structname>pg_attrdef</structname> stores column default values. The main information
about columns is stored in <structname>pg_attribute</structname>
(see below). Only columns that explicitly specify a default value
(when the table is created or the column is added) will have an
</para>
<table>
- <title>pg_attrdef Columns</title>
+ <title><structname>pg_attrdef</> Columns</title>
<tgroup cols=4>
<thead>
<tbody>
<row>
- <entry>adrelid</entry>
+ <entry><structfield>adrelid</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_class.oid</entry>
+ <entry><literal>pg_class.oid</literal></entry>
<entry>The table this column belongs to</entry>
</row>
<row>
- <entry>adnum</entry>
+ <entry><structfield>adnum</structfield></entry>
<entry><type>int2</type></entry>
- <entry>pg_attribute.attnum</entry>
+ <entry><literal>pg_attribute.attnum</literal></entry>
<entry>The number of the column</entry>
</row>
<row>
- <entry>adbin</entry>
+ <entry><structfield>adbin</structfield></entry>
<entry><type>text</type></entry>
<entry></entry>
- <entry>An internal representation of the column default value</entry>
+ <entry>The internal representation of the column default value</entry>
</row>
<row>
- <entry>adsrc</entry>
+ <entry><structfield>adsrc</structfield></entry>
<entry><type>text</type></entry>
<entry></entry>
<entry>A human-readable representation of the default value</entry>
<sect1 id="catalog-pg-attribute">
- <title>pg_attribute</title>
+ <title><structname>pg_attribute</structname></title>
+
+ <indexterm zone="catalog-pg-attribute">
+ <primary>pg_attribute</primary>
+ </indexterm>
<para>
- <structname>pg_attribute</structname> stores information about
+ The catalog <structname>pg_attribute</structname> stores information about
table columns. There will be exactly one
<structname>pg_attribute</structname> row for every column in every
table in the database. (There will also be attribute entries for
</para>
<table>
- <title>pg_attribute Columns</title>
+ <title><structname>pg_attribute</> Columns</title>
<tgroup cols=4>
<thead>
<tbody>
<row>
- <entry>attrelid</entry>
+ <entry><structfield>attrelid</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_class.oid</entry>
+ <entry><literal>pg_class.oid</literal></entry>
<entry>The table this column belongs to</entry>
</row>
<row>
- <entry>attname</entry>
+ <entry><structfield>attname</structfield></entry>
<entry><type>name</type></entry>
<entry></entry>
- <entry>Column name</entry>
+ <entry>The column name</entry>
</row>
<row>
- <entry>atttypid</entry>
+ <entry><structfield>atttypid</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_type.oid</entry>
+ <entry><literal>pg_type.oid</literal></entry>
<entry>The data type of this column</entry>
</row>
<row>
- <entry>attstattarget</entry>
+ <entry><structfield>attstattarget</structfield></entry>
<entry><type>int4</type></entry>
<entry></entry>
<entry>
<command>ANALYZE</command>.
A zero value indicates that no statistics should be collected.
A negative value says to use the system default statistics target.
- The exact meaning of positive values is datatype-dependent.
- For scalar datatypes, <structfield>attstattarget</structfield>
+ The exact meaning of positive values is data type-dependent.
+ For scalar data types, <structfield>attstattarget</structfield>
is both the target number of <quote>most common values</quote>
to collect, and the target number of histogram bins to create.
</entry>
</row>
<row>
- <entry>attlen</entry>
+ <entry><structfield>attlen</structfield></entry>
<entry><type>int2</type></entry>
<entry></entry>
<entry>
- This is a copy of
- <structname>pg_type</structname>.<structfield>typlen</structfield>
- of this column's type.
+ A copy of <literal>pg_type.typlen</literal> of this column's
+ type
</entry>
</row>
<row>
- <entry>attnum</entry>
+ <entry><structfield>attnum</structfield></entry>
<entry><type>int2</type></entry>
<entry></entry>
<entry>
</row>
<row>
- <entry>attndims</entry>
+ <entry><structfield>attndims</structfield></entry>
<entry><type>int4</type></entry>
<entry></entry>
<entry>
</row>
<row>
- <entry>attcacheoff</entry>
+ <entry><structfield>attcacheoff</structfield></entry>
<entry><type>int4</type></entry>
<entry></entry>
<entry>
</row>
<row>
- <entry>atttypmod</entry>
+ <entry><structfield>atttypmod</structfield></entry>
<entry><type>int4</type></entry>
<entry></entry>
<entry>
supplied at table creation time (for example, the maximum
length of a <type>varchar</type> column). It is passed to
type-specific input functions and length coercion functions.
- The value will generally be -1 for types that do not need typmod.
+ The value will generally be -1 for types that do not need <structfield>atttypmod</>.
</entry>
</row>
<row>
- <entry>attbyval</entry>
+ <entry><structfield>attbyval</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>
- A copy of
- <structname>pg_type</structname>.<structfield>typbyval</structfield>
- of this column's type
+ A copy of <literal>pg_type.typbyval</> of this column's type
</entry>
</row>
<row>
- <entry>attstorage</entry>
+ <entry><structfield>attstorage</structfield></entry>
<entry><type>char</type></entry>
<entry></entry>
<entry>
- Normally a copy of
- <structname>pg_type</structname>.<structfield>typstorage</structfield>
- of this column's type. For TOASTable datatypes, this can be altered
+ Normally a copy of <literal>pg_type.typstorage</> of this
+ column's type. For TOAST-able data types, this can be altered
after column creation to control storage policy.
</entry>
</row>
<row>
- <entry>attisset</entry>
+ <entry><structfield>attisset</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>
stored in the attribute is the OID of a tuple in the
<structname>pg_proc</structname> catalog. The
<structname>pg_proc</structname> tuple contains the query
- string that defines this set - i.e., the query to run to get
+ string that defines this set, i.e., the query to run to get
the set. So the <structfield>atttypid</structfield> (see
above) refers to the type returned by this query, but the
actual length of this attribute is the length (size) of an
</row>
<row>
- <entry>attalign</entry>
+ <entry><structfield>attalign</structfield></entry>
<entry><type>char</type></entry>
<entry></entry>
<entry>
- A copy of
- <structname>pg_type</structname>.<structfield>typalign</structfield>
- of this column's type
+ A copy of <literal>pg_type.typalign</> of this column's type
</entry>
</row>
<row>
- <entry>attnotnull</entry>
+ <entry><structfield>attnotnull</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>
- This represents a NOT NULL constraint. It is possible to
- change this field to enable or disable the constraint.
+ This represents a not-null constraint. It is possible to
+ change this column to enable or disable the constraint.
</entry>
</row>
<row>
- <entry>atthasdef</entry>
+ <entry><structfield>atthasdef</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>
</row>
<row>
- <entry>attisdropped</entry>
+ <entry><structfield>attisdropped</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>
</row>
<row>
- <entry>attislocal</entry>
+ <entry><structfield>attislocal</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>
</row>
<row>
- <entry>attinhcount</entry>
+ <entry><structfield>attinhcount</structfield></entry>
<entry><type>int4</type></entry>
<entry></entry>
<entry>
<sect1 id="catalog-pg-cast">
- <title>pg_cast</title>
+ <title><structname>pg_cast</structname></title>
+
+ <indexterm zone="catalog-pg-cast">
+ <primary>pg_cast</primary>
+ </indexterm>
<para>
- <structname>pg_cast</structname> stores data type conversion paths,
+ The catalog <structname>pg_cast</structname> stores data type conversion paths,
both built-in paths and those defined with <command>CREATE CAST</command>.
</para>
<table>
- <title>pg_cast Columns</title>
+ <title><structfield>pg_cast</> Columns</title>
<tgroup cols=4>
<thead>
<tbody>
<row>
- <entry>castsource</entry>
+ <entry><structfield>castsource</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_type.oid</entry>
+ <entry><literal>pg_type.oid</literal></entry>
<entry>OID of the source data type</entry>
</row>
<row>
- <entry>casttarget</entry>
+ <entry><structfield>casttarget</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_type.oid</entry>
+ <entry><literal>pg_type.oid</literal></entry>
<entry>OID of the target data type</entry>
</row>
<row>
- <entry>castfunc</entry>
+ <entry><structfield>castfunc</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_proc.oid</entry>
+ <entry><literal>pg_proc.oid</literal></entry>
<entry>
The OID of the function to use to perform this cast. Zero is
- stored if the data types are binary coercible (that is, no
+ stored if the data types are binary compatible (that is, no
run-time operation is needed to perform the cast).
</entry>
</row>
<row>
- <entry>castcontext</entry>
+ <entry><structfield>castcontext</structfield></entry>
<entry><type>char</type></entry>
<entry></entry>
<entry>
</sect1>
<sect1 id="catalog-pg-class">
- <title>pg_class</title>
+ <title><structname>pg_class</structname></title>
+
+ <indexterm zone="catalog-pg-class">
+ <primary>pg_class</primary>
+ </indexterm>
<para>
- <structname>pg_class</structname> catalogs tables and most
+ The catalog <structname>pg_class</structname> catalogs tables and most
everything else that has columns or is otherwise similar to a
table. This includes indexes (but see also
<structname>pg_index</structname>), sequences, views, and some
kinds of special relation; see <structfield>relkind</>.
Below, when we mean all of these
kinds of objects we speak of <quote>relations</quote>. Not all
- fields are meaningful for all relation types.
+ columns are meaningful for all relation types.
</para>
<table>
- <title>pg_class Columns</title>
+ <title><structname>pg_class</> Columns</title>
<tgroup cols=4>
<thead>
<tbody>
<row>
- <entry>relname</entry>
+ <entry><structfield>relname</structfield></entry>
<entry><type>name</type></entry>
<entry></entry>
<entry>Name of the table, index, view, etc.</entry>
</row>
<row>
- <entry>relnamespace</entry>
+ <entry><structfield>relnamespace</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_namespace.oid</entry>
+ <entry><literal>pg_namespace.oid</literal></entry>
<entry>
The OID of the namespace that contains this relation
</entry>
</row>
<row>
- <entry>reltype</entry>
+ <entry><structfield>reltype</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_type.oid</entry>
+ <entry><literal>pg_type.oid</literal></entry>
<entry>
The OID of the data type that corresponds to this table, if any
- (zero for indexes, which have no pg_type entry)
+ (zero for indexes, which have no <structname>pg_type</> entry)
</entry>
</row>
<row>
- <entry>relowner</entry>
+ <entry><structfield>relowner</structfield></entry>
<entry><type>int4</type></entry>
- <entry>pg_shadow.usesysid</entry>
+ <entry><literal>pg_shadow.usesysid</literal></entry>
<entry>Owner of the relation</entry>
</row>
<row>
- <entry>relam</entry>
+ <entry><structfield>relam</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_am.oid</entry>
+ <entry><literal>pg_am.oid</literal></entry>
<entry>If this is an index, the access method used (B-tree, hash, etc.)</entry>
</row>
<row>
- <entry>relfilenode</entry>
+ <entry><structfield>relfilenode</structfield></entry>
<entry><type>oid</type></entry>
<entry></entry>
<entry>Name of the on-disk file of this relation; 0 if none</entry>
</row>
<row>
- <entry>relpages</entry>
+ <entry><structfield>relpages</structfield></entry>
<entry><type>int4</type></entry>
<entry></entry>
<entry>
</row>
<row>
- <entry>reltuples</entry>
+ <entry><structfield>reltuples</structfield></entry>
<entry><type>float4</type></entry>
<entry></entry>
<entry>
</row>
<row>
- <entry>reltoastrelid</entry>
+ <entry><structfield>reltoastrelid</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_class.oid</entry>
+ <entry><literal>pg_class.oid</literal></entry>
<entry>
OID of the TOAST table associated with this table, 0 if none.
The TOAST table stores large attributes <quote>out of
</row>
<row>
- <entry>reltoastidxid</entry>
+ <entry><structfield>reltoastidxid</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_class.oid</entry>
+ <entry><literal>pg_class.oid</literal></entry>
<entry>
For a TOAST table, the OID of its index. 0 if not a TOAST table.
</entry>
</row>
<row>
- <entry>relhasindex</entry>
+ <entry><structfield>relhasindex</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>
True if this is a table and it has (or recently had) any
indexes. This is set by <command>CREATE INDEX</command>, but
not cleared immediately by <command>DROP INDEX</command>.
- <command>VACUUM</command> clears relhasindex if it finds the
+ <command>VACUUM</command> clears <structfield>relhasindex</> if it finds the
table has no indexes.
</entry>
</row>
<row>
- <entry>relisshared</entry>
+ <entry><structfield>relisshared</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>True if this table is shared across all databases in the
</row>
<row>
- <entry>relkind</entry>
+ <entry><structfield>relkind</structfield></entry>
<entry><type>char</type></entry>
<entry></entry>
<entry>
- 'r' = ordinary table, 'i' = index, 'S' = sequence, 'v' = view,
- 'c' = composite type, 's' = special, 't' = TOAST table
+ <literal>r</> = ordinary table, <literal>i</> = index,
+ <literal>S</> = sequence, <literal>v</> = view, <literal>c</> =
+ composite type, <literal>s</> = special, <literal>t</> = TOAST
+ table
</entry>
</row>
<row>
- <entry>relnatts</entry>
+ <entry><structfield>relnatts</structfield></entry>
<entry><type>int2</type></entry>
<entry></entry>
<entry>
- Number of user columns in the relation (system columns not counted).
- There must be this many corresponding entries in
+ Number of user columns in the relation (system columns not
+ counted). There must be this many corresponding entries in
<structname>pg_attribute</structname>. See also
- <structname>pg_attribute</structname>.<structfield>attnum</structfield>.
+ <literal>pg_attribute.attnum</literal>.
</entry>
</row>
<row>
- <entry>relchecks</entry>
+ <entry><structfield>relchecks</structfield></entry>
<entry><type>int2</type></entry>
<entry></entry>
<entry>
</row>
<row>
- <entry>reltriggers</entry>
+ <entry><structfield>reltriggers</structfield></entry>
<entry><type>int2</type></entry>
<entry></entry>
<entry>
</row>
<row>
- <entry>relukeys</entry>
+ <entry><structfield>relukeys</structfield></entry>
<entry><type>int2</type></entry>
<entry></entry>
- <entry>unused (<emphasis>Not</emphasis> the number of unique keys)</entry>
+ <entry>unused (<emphasis>not</emphasis> the number of unique keys)</entry>
</row>
<row>
- <entry>relfkeys</entry>
+ <entry><structfield>relfkeys</structfield></entry>
<entry><type>int2</type></entry>
<entry></entry>
- <entry>unused (<emphasis>Not</emphasis> the number of foreign keys on the table)</entry>
+ <entry>unused (<emphasis>not</emphasis> the number of foreign keys on the table)</entry>
</row>
<row>
- <entry>relrefs</entry>
+ <entry><structfield>relrefs</structfield></entry>
<entry><type>int2</type></entry>
<entry></entry>
<entry>unused</entry>
</row>
<row>
- <entry>relhasoids</entry>
+ <entry><structfield>relhasoids</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>
</row>
<row>
- <entry>relhaspkey</entry>
+ <entry><structfield>relhaspkey</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>
</row>
<row>
- <entry>relhasrules</entry>
+ <entry><structfield>relhasrules</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>Table has rules; see
</row>
<row>
- <entry>relhassubclass</entry>
+ <entry><structfield>relhassubclass</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>At least one table inherits from this one</entry>
</row>
<row>
- <entry>relacl</entry>
+ <entry><structfield>relacl</structfield></entry>
<entry><type>aclitem[]</type></entry>
<entry></entry>
<entry>
- Access permissions. See the descriptions of
+ Access privileges; see the descriptions of
<command>GRANT</command> and <command>REVOKE</command> for
details.
</entry>
</sect1>
<sect1 id="catalog-pg-constraint">
- <title>pg_constraint</title>
+ <title><structname>pg_constraint</structname></title>
+
+ <indexterm zone="catalog-pg-constraint">
+ <primary>pg_constraint</primary>
+ </indexterm>
<para>
- This system catalog stores CHECK, PRIMARY KEY, UNIQUE, and FOREIGN KEY
- constraints on tables. (Column
- constraints are not treated specially. Every column constraint is
- equivalent to some table constraint.) See under <command>CREATE
- TABLE</command> for more information.
+ The catalog <structname>pg_constraint</structname> stores check, primary key, unique, and foreign
+ key constraints on tables. (Column constraints are not treated
+ specially. Every column constraint is equivalent to some table
+ constraint.) Not-null constraints are represented in the
+ <structname>pg_attribute</> catalog.
</para>
- <note>
- <para>
- NOT NULL constraints are represented in the <structname>pg_attribute</>
- catalog.
- </para>
- </note>
-
<para>
- CHECK constraints on domains are stored here, too. Global ASSERTIONS
- (a currently-unsupported SQL feature) may someday appear here as well.
+ Check constraints on domains are stored here, too.
</para>
<table>
- <title>pg_constraint Columns</title>
+ <title><structname>pg_constraint</> Columns</title>
<tgroup cols=4>
<thead>
<tbody>
<row>
- <entry>conname</entry>
+ <entry><structfield>conname</structfield></entry>
<entry><type>name</type></entry>
<entry></entry>
<entry>Constraint name (not necessarily unique!)</entry>
</row>
<row>
- <entry>connamespace</entry>
+ <entry><structfield>connamespace</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_namespace.oid</entry>
+ <entry><literal>pg_namespace.oid</literal></entry>
<entry>
The OID of the namespace that contains this constraint
</entry>
</row>
<row>
- <entry>contype</entry>
+ <entry><structfield>contype</structfield></entry>
<entry><type>char</type></entry>
<entry></entry>
<entry>
- 'c' = check constraint,
- 'f' = foreign key constraint,
- 'p' = primary key constraint,
- 'u' = unique constraint
+ <literal>c</> = check constraint,
+ <literal>f</> = foreign key constraint,
+ <literal>p</> = primary key constraint,
+ <literal>u</> = unique constraint
</entry>
</row>
<row>
- <entry>condeferrable</entry>
- <entry><type>boolean</type></entry>
+ <entry><structfield>condeferrable</structfield></entry>
+ <entry><type>bool</type></entry>
<entry></entry>
<entry>Is the constraint deferrable?</entry>
</row>
<row>
- <entry>condeferred</entry>
- <entry><type>boolean</type></entry>
+ <entry><structfield>condeferred</structfield></entry>
+ <entry><type>bool</type></entry>
<entry></entry>
<entry>Is the constraint deferred by default?</entry>
</row>
<row>
- <entry>conrelid</entry>
+ <entry><structfield>conrelid</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_class.oid</entry>
+ <entry><literal>pg_class.oid</literal></entry>
<entry>The table this constraint is on; 0 if not a table constraint</entry>
</row>
<row>
- <entry>contypid</entry>
+ <entry><structfield>contypid</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_type.oid</entry>
+ <entry><literal>pg_type.oid</literal></entry>
<entry>The domain this constraint is on; 0 if not a domain constraint</entry>
</row>
<row>
- <entry>confrelid</entry>
+ <entry><structfield>confrelid</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_class.oid</entry>
+ <entry><literal>pg_class.oid</literal></entry>
<entry>If a foreign key, the referenced table; else 0</entry>
</row>
<row>
- <entry>confupdtype</entry>
+ <entry><structfield>confupdtype</structfield></entry>
<entry><type>char</type></entry>
<entry></entry>
<entry>Foreign key update action code</entry>
</row>
<row>
- <entry>confdeltype</entry>
+ <entry><structfield>confdeltype</structfield></entry>
<entry><type>char</type></entry>
<entry></entry>
<entry>Foreign key deletion action code</entry>
</row>
<row>
- <entry>confmatchtype</entry>
+ <entry><structfield>confmatchtype</structfield></entry>
<entry><type>char</type></entry>
<entry></entry>
<entry>Foreign key match type</entry>
</row>
<row>
- <entry>conkey</entry>
+ <entry><structfield>conkey</structfield></entry>
<entry><type>int2[]</type></entry>
- <entry>pg_attribute.attnum</entry>
+ <entry><literal>pg_attribute.attnum</></entry>
<entry>If a table constraint, list of columns which the constraint constrains</entry>
</row>
<row>
- <entry>confkey</entry>
+ <entry><structfield>confkey</structfield></entry>
<entry><type>int2[]</type></entry>
- <entry>pg_attribute.attnum</entry>
+ <entry><literal>pg_attribute.attnum</></entry>
<entry>If a foreign key, list of the referenced columns</entry>
</row>
<row>
- <entry>conbin</entry>
+ <entry><structfield>conbin</structfield></entry>
<entry><type>text</type></entry>
<entry></entry>
<entry>If a check constraint, an internal representation of the expression</entry>
</row>
<row>
- <entry>consrc</entry>
+ <entry><structfield>consrc</structfield></entry>
<entry><type>text</type></entry>
<entry></entry>
<entry>If a check constraint, a human-readable representation of the expression</entry>
<note>
<para>
- <structname>pg_class</structname>.<structfield>relchecks</structfield>
- needs to agree with the number of check-constraint entries found in this
- table for the given relation.
+ <literal>pg_class.relchecks</literal> needs to agree with the
+ number of check-constraint entries found in this table for the
+ given relation.
</para>
</note>
</sect1>
<sect1 id="catalog-pg-conversion">
- <title>pg_conversion</title>
+ <title><structname>pg_conversion</structname></title>
+
+ <indexterm zone="catalog-pg-conversion">
+ <primary>pg_conversion</primary>
+ </indexterm>
<para>
- This system catalog stores encoding conversion information. See
+ The catalog <structname>pg_conversion</structname> stores encoding conversion information. See
<command>CREATE CONVERSION</command> for more information.
</para>
<table>
- <title>pg_conversion Columns</title>
+ <title><structname>pg_conversion</> Columns</title>
<tgroup cols=4>
<thead>
<tbody>
<row>
- <entry>conname</entry>
+ <entry><structfield>conname</structfield></entry>
<entry><type>name</type></entry>
<entry></entry>
<entry>Conversion name (unique within a namespace)</entry>
</row>
<row>
- <entry>connamespace</entry>
+ <entry><structfield>connamespace</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_namespace.oid</entry>
+ <entry><literal>pg_namespace.oid</literal></entry>
<entry>
The OID of the namespace that contains this conversion
</entry>
</row>
<row>
- <entry>conowner</entry>
+ <entry><structfield>conowner</structfield></entry>
<entry><type>int4</type></entry>
- <entry>pg_shadow.usesysid</entry>
- <entry>Owner (creator) of the namespace</entry>
+ <entry><literal>pg_shadow.usesysid</literal></entry>
+ <entry>Owner of the conversion</entry>
</row>
<row>
- <entry>conforencoding</entry>
+ <entry><structfield>conforencoding</structfield></entry>
<entry><type>int4</type></entry>
<entry></entry>
- <entry>Source(for) encoding ID</entry>
+ <entry>Source encoding ID</entry>
</row>
<row>
- <entry>contoencoding</entry>
+ <entry><structfield>contoencoding</structfield></entry>
<entry><type>int4</type></entry>
<entry></entry>
- <entry>Destination(to) encoding ID</entry>
+ <entry>Destination encoding ID</entry>
</row>
<row>
- <entry>conproc</entry>
+ <entry><structfield>conproc</structfield></entry>
<entry><type>regproc</type></entry>
- <entry>pg_proc.oid</entry>
+ <entry><literal>pg_proc.oid</literal></entry>
<entry>Conversion procedure</entry>
</row>
<row>
- <entry>condefault</entry>
- <entry><type>boolean</type></entry>
+ <entry><structfield>condefault</structfield></entry>
+ <entry><type>bool</type></entry>
<entry></entry>
- <entry>true if this is the default conversion</entry>
+ <entry>True if this is the default conversion</entry>
</row>
</tbody>
</sect1>
<sect1 id="catalog-pg-database">
- <title>pg_database</title>
+ <title><structname>pg_database</structname></title>
+
+ <indexterm zone="catalog-pg-database">
+ <primary>pg_database</primary>
+ </indexterm>
<para>
- The <structname>pg_database</structname> catalog stores information
+ The catalog <structname>pg_database</structname> stores information
about the available databases. Databases are created with the
<command>CREATE DATABASE</command> command. Consult
<xref linkend="managing-databases"> for details about the meaning of some of the
</para>
<table>
- <title>pg_database Columns</title>
+ <title><structname>pg_database</> Columns</title>
<tgroup cols=4>
<thead>
<tbody>
<row>
- <entry>datname</entry>
+ <entry><structfield>datname</structfield></entry>
<entry><type>name</type></entry>
<entry></entry>
<entry>Database name</entry>
</row>
<row>
- <entry>datdba</entry>
+ <entry><structfield>datdba</structfield></entry>
<entry><type>int4</type></entry>
- <entry>pg_shadow.usesysid</entry>
+ <entry><literal>pg_shadow.usesysid</literal></entry>
<entry>Owner of the database, usually the user who created it</entry>
</row>
<row>
- <entry>encoding</entry>
+ <entry><structfield>encoding</structfield></entry>
<entry><type>int4</type></entry>
<entry></entry>
- <entry>Character/multibyte encoding for this database</entry>
+ <entry>Character encoding for this database</entry>
</row>
<row>
- <entry>datistemplate</entry>
+ <entry><structfield>datistemplate</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>
If true then this database can be used in the
- <quote>TEMPLATE</quote> clause of <command>CREATE
+ <literal>TEMPLATE</literal> clause of <command>CREATE
DATABASE</command> to create a new database as a clone of
this one.
</entry>
</row>
<row>
- <entry>datallowconn</entry>
+ <entry><structfield>datallowconn</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>
If false then no one can connect to this database. This is
- used to protect the template0 database from being altered.
+ used to protect the <literal>template0</> database from being altered.
</entry>
</row>
<row>
- <entry>datlastsysoid</entry>
+ <entry><structfield>datlastsysoid</structfield></entry>
<entry><type>oid</type></entry>
<entry></entry>
<entry>
</row>
<row>
- <entry>datvacuumxid</entry>
+ <entry><structfield>datvacuumxid</structfield></entry>
<entry><type>xid</type></entry>
<entry></entry>
<entry>
</row>
<row>
- <entry>datfrozenxid</entry>
+ <entry><structfield>datfrozenxid</structfield></entry>
<entry><type>xid</type></entry>
<entry></entry>
<entry>
All tuples inserted by transaction IDs before this one have been
relabeled with a permanent (<quote>frozen</>) transaction ID in this
database. This is useful to check whether a database must be vacuumed
- soon to avoid transaction ID wraparound problems.
+ soon to avoid transaction ID wrap-around problems.
</entry>
</row>
<row>
- <entry>datpath</entry>
+ <entry><structfield>datpath</structfield></entry>
<entry><type>text</type></entry>
<entry></entry>
<entry>
</row>
<row>
- <entry>datconfig</entry>
+ <entry><structfield>datconfig</structfield></entry>
<entry><type>text[]</type></entry>
<entry></entry>
<entry>Session defaults for run-time configuration variables</entry>
</row>
<row>
- <entry>datacl</entry>
+ <entry><structfield>datacl</structfield></entry>
<entry><type>aclitem[]</type></entry>
<entry></entry>
- <entry>Access permissions</entry>
+ <entry>Access privileges</entry>
</row>
</tbody>
</tgroup>
<sect1 id="catalog-pg-depend">
- <title>pg_depend</title>
+ <title><structname>pg_depend</structname></title>
+
+ <indexterm zone="catalog-pg-depend">
+ <primary>pg_depend</primary>
+ </indexterm>
<para>
- The <structname>pg_depend</structname> table records the dependency
+ The catalog <structname>pg_depend</structname> records the dependency
relationships between database objects. This information allows
<command>DROP</> commands to find which other objects must be dropped
- by <command>DROP CASCADE</>, or prevent dropping in the <command>DROP
+ by <command>DROP CASCADE</> or prevent dropping in the <command>DROP
RESTRICT</> case.
</para>
<table>
- <title>pg_depend Columns</title>
+ <title><structname>pg_depend</> Columns</title>
<tgroup cols=4>
<thead>
<tbody>
<row>
- <entry>classid</entry>
+ <entry><structfield>classid</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_class.oid</entry>
- <entry>The oid of the system catalog the dependent object is in</entry>
+ <entry><literal>pg_class.oid</literal></entry>
+ <entry>The OID of the system catalog the dependent object is in</entry>
</row>
<row>
- <entry>objid</entry>
+ <entry><structfield>objid</structfield></entry>
<entry><type>oid</type></entry>
- <entry>any oid attribute</entry>
- <entry>The oid of the specific dependent object</entry>
+ <entry>any OID column</entry>
+ <entry>The OID of the specific dependent object</entry>
</row>
<row>
- <entry>objsubid</entry>
+ <entry><structfield>objsubid</structfield></entry>
<entry><type>int4</type></entry>
<entry></entry>
- <entry>For a table attribute, this is the attribute's
- column number (the objid and classid refer to the table itself).
- For all other object types, this field is presently zero.
+ <entry>
+ For a table column, this is the column number (the
+ <structfield>objid</> and <structfield>classid</> refer to the
+ table itself). For all other object types, this column is
+ zero.
</entry>
</row>
<row>
- <entry>refclassid</entry>
+ <entry><structfield>refclassid</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_class.oid</entry>
- <entry>The oid of the system catalog the referenced object is in</entry>
+ <entry><literal>pg_class.oid</literal></entry>
+ <entry>The OID of the system catalog the referenced object is in</entry>
</row>
<row>
- <entry>refobjid</entry>
+ <entry><structfield>refobjid</structfield></entry>
<entry><type>oid</type></entry>
<entry>any oid attribute</entry>
- <entry>The oid of the specific referenced object</entry>
+ <entry>The OID of the specific referenced object</entry>
</row>
<row>
- <entry>refobjsubid</entry>
+ <entry><structfield>refobjsubid</structfield></entry>
<entry><type>int4</type></entry>
<entry></entry>
- <entry>For a table attribute, this is the attribute's
- column number (the refobjid and refclassid refer to the table itself).
- For all other object types, this field is presently zero.
+ <entry>
+ For a table column, this is the column number (the
+ <structfield>refobjid</> and <structfield>refclassid</> refer
+ to the table itself). For all other object types, this column
+ is zero.
</entry>
</row>
<row>
- <entry>deptype</entry>
+ <entry><structfield>deptype</structfield></entry>
<entry><type>char</type></entry>
<entry></entry>
<entry>
- A code defining the specific semantics of this dependency relationship.
+ A code defining the specific semantics of this dependency relationship; see text.
</entry>
</row>
object. However, there are several subflavors identified by
<structfield>deptype</>:
- <itemizedlist>
- <listitem>
- <para>
- DEPENDENCY_NORMAL ('n'): normal relationship between separately-created
- objects. The dependent object may be dropped without affecting the
- referenced object. The referenced object may only be dropped by
- specifying CASCADE, in which case the dependent object is dropped too.
- Example: a table column has a normal dependency on its datatype.
- </para>
- </listitem>
-
- <listitem>
- <para>
- DEPENDENCY_AUTO ('a'): the dependent object can be dropped separately
- from the referenced object, and should be automatically dropped
- (regardless of RESTRICT or CASCADE mode) if the referenced object
- is dropped.
- Example: a named constraint on a table is made auto-dependent on
- the table, so that it will go away if the table is dropped.
- </para>
- </listitem>
-
- <listitem>
- <para>
- DEPENDENCY_INTERNAL ('i'): the dependent object was created as part
- of creation of the referenced object, and is really just a part of
- its internal implementation. A DROP of the dependent object will be
- disallowed outright (we'll tell the user to issue a DROP against the
- referenced object, instead). A DROP of the referenced object will be
- propagated through to drop the dependent object whether CASCADE is
- specified or not.
- Example: a trigger that's created to enforce a foreign-key constraint
- is made internally dependent on the constraint's pg_constraint entry.
- </para>
- </listitem>
-
- <listitem>
- <para>
- DEPENDENCY_PIN ('p'): there is no dependent object; this type of entry
- is a signal that the system itself depends on the referenced object,
- and so that object must never be deleted. Entries of this type are
- created only during initdb. The fields for the dependent object
- contain zeroes.
- </para>
- </listitem>
- </itemizedlist>
+ <variablelist>
+ <varlistentry>
+ <term><symbol>DEPENDENCY_NORMAL</> (<literal>n</>)</term>
+ <listitem>
+ <para>
+ A normal relationship between separately-created objects. The
+ dependent object may be dropped without affecting the
+ referenced object. The referenced object may only be dropped
+ by specifying <literal>CASCADE</>, in which case the dependent
+ object is dropped, too. Example: a table column has a normal
+ dependency on its data type.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><symbol>DEPENDENCY_AUTO</> (<literal>a</>)</term>
+ <listitem>
+ <para>
+ The dependent object can be dropped separately from the
+ referenced object, and should be automatically dropped
+ (regardless of <literal>RESTRICT</> or <literal>CASCADE</>
+ mode) if the referenced object is dropped. Example: a named
+ constraint on a table is made autodependent on the table, so
+ that it will go away if the table is dropped.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><symbol>DEPENDENCY_INTERNAL</> (<literal>i</>)</term>
+ <listitem>
+ <para>
+ The dependent object was created as part of creation of the
+ referenced object, and is really just a part of its internal
+ implementation. A <command>DROP</> of the dependent object
+ will be disallowed outright (we'll tell the user to issue a
+ <command>DROP</> against the referenced object, instead). A
+ <command>DROP</> of the referenced object will be propagated
+ through to drop the dependent object whether
+ <command>CASCADE</> is specified or not. Example: a trigger
+ that's created to enforce a foreign-key constraint is made
+ internally dependent on the constraint's
+ <structname>pg_constraint</> entry.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><symbol>DEPENDENCY_PIN</> (<literal>p</>)</term>
+ <listitem>
+ <para>
+ There is no dependent object; this type of entry is a signal
+ that the system itself depends on the referenced object, and so
+ that object must never be deleted. Entries of this type are
+ created only by <command>initdb</command>. The columns for the
+ dependent object contain zeroes.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
Other dependency flavors may be needed in future.
</para>
<sect1 id="catalog-pg-description">
- <title>pg_description</title>
+ <title><structname>pg_description</structname></title>
+
+ <indexterm zone="catalog-pg-description">
+ <primary>pg_description</primary>
+ </indexterm>
<para>
- The pg_description table can store an optional description or
+ The catalog <structname>pg_description</> can store an optional description or
comment for each database object. Descriptions can be manipulated
with the <command>COMMENT</command> command and viewed with
<application>psql</application>'s <literal>\d</literal> commands.
Descriptions of many built-in system objects are provided in the initial
- contents of pg_description.
+ contents of <structname>pg_description</structname>.
</para>
<table>
- <title>pg_description Columns</title>
+ <title><structname>pg_description</> Columns</title>
<tgroup cols=4>
<thead>
<tbody>
<row>
- <entry>objoid</entry>
+ <entry><structfield>objoid</structfield></entry>
<entry><type>oid</type></entry>
- <entry>any oid attribute</entry>
- <entry>The oid of the object this description pertains to</entry>
+ <entry>any OID column</entry>
+ <entry>The OID of the object this description pertains to</entry>
</row>
<row>
- <entry>classoid</entry>
+ <entry><structfield>classoid</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_class.oid</entry>
- <entry>The oid of the system catalog this object appears in</entry>
+ <entry><literal>pg_class.oid</literal></entry>
+ <entry>The OID of the system catalog this object appears in</entry>
</row>
<row>
- <entry>objsubid</entry>
+ <entry><structfield>objsubid</structfield></entry>
<entry><type>int4</type></entry>
<entry></entry>
- <entry>For a comment on a table attribute, this is the attribute's
- column number (the objoid and classoid refer to the table itself).
- For all other object types, this field is presently zero.
+ <entry>
+ For a comment on a table column, this is the column number (the
+ <structfield>objoid</> and <structfield>classoid</> refer to
+ the table itself). For all other object types, this column is
+ zero.
</entry>
</row>
<row>
- <entry>description</entry>
+ <entry><structfield>description</structfield></entry>
<entry><type>text</type></entry>
<entry></entry>
<entry>Arbitrary text that serves as the description of this object.</entry>
<sect1 id="catalog-pg-group">
- <title>pg_group</title>
+ <title><structname>pg_group</structname></title>
+
+ <indexterm zone="catalog-pg-group">
+ <primary>pg_group</primary>
+ </indexterm>
<para>
- This catalog defines groups and stores what users belong to what
+ The catalog <structname>pg_group</structname> defines groups and stores what users belong to what
groups. Groups are created with the <command>CREATE
GROUP</command> command. Consult <xref linkend="user-manag"> for information
- about user permission management.
+ about user privilege management.
</para>
<para>
</para>
<table>
- <title>pg_group Columns</title>
+ <title><structname>pg_group</> Columns</title>
<tgroup cols=4>
<thead>
<tbody>
<row>
- <entry>groname</entry>
+ <entry><structfield>groname</structfield></entry>
<entry><type>name</type></entry>
<entry></entry>
<entry>Name of the group</entry>
</row>
<row>
- <entry>grosysid</entry>
+ <entry><structfield>grosysid</structfield></entry>
<entry><type>int4</type></entry>
<entry></entry>
<entry>An arbitrary number to identify this group</entry>
</row>
<row>
- <entry>grolist</entry>
+ <entry><structfield>grolist</structfield></entry>
<entry><type>int4[]</type></entry>
- <entry>pg_shadow.usesysid</entry>
- <entry>An array containing the ids of the users in this group</entry>
+ <entry><literal>pg_shadow.usesysid</literal></entry>
+ <entry>An array containing the IDs of the users in this group</entry>
</row>
</tbody>
</tgroup>
<sect1 id="catalog-pg-index">
- <title>pg_index</title>
+ <title><structname>pg_index</structname></title>
+
+ <indexterm zone="catalog-pg-index">
+ <primary>pg_index</primary>
+ </indexterm>
<para>
- <structname>pg_index</structname> contains part of the information
+ The catalog <structname>pg_index</structname> contains part of the information
about indexes. The rest is mostly in
<structname>pg_class</structname>.
</para>
<table>
- <title>pg_index Columns</title>
+ <title><structname>pg_index</> Columns</title>
<tgroup cols=4>
<thead>
<tbody>
<row>
- <entry>indexrelid</entry>
+ <entry><structfield>indexrelid</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_class.oid</entry>
- <entry>The OID of the pg_class entry for this index</entry>
+ <entry><literal>pg_class.oid</literal></entry>
+ <entry>The OID of the <structname>pg_class</> entry for this index</entry>
</row>
<row>
- <entry>indrelid</entry>
+ <entry><structfield>indrelid</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_class.oid</entry>
- <entry>The OID of the pg_class entry for the table this index is for</entry>
+ <entry><literal>pg_class.oid</literal></entry>
+ <entry>The OID of the <structname>pg_class</> entry for the table this index is for</entry>
</row>
<row>
- <entry>indproc</entry>
+ <entry><structfield>indproc</structfield></entry>
<entry><type>regproc</type></entry>
- <entry>pg_proc.oid</entry>
+ <entry><literal>pg_proc.oid</literal></entry>
<entry>The function's OID if this is a functional index,
else zero</entry>
</row>
<row>
- <entry>indkey</entry>
+ <entry><structfield>indkey</structfield></entry>
<entry><type>int2vector</type></entry>
<entry>pg_attribute.attnum</entry>
<entry>
- This is a vector (array) of up to
+ This is an array of up to
<symbol>INDEX_MAX_KEYS</symbol> values that indicate which
table columns this index pertains to. For example a value of
<literal>1 3</literal> would mean that the first and the third
</row>
<row>
- <entry>indclass</entry>
+ <entry><structfield>indclass</structfield></entry>
<entry><type>oidvector</type></entry>
<entry>pg_opclass.oid</entry>
<entry>
For each column in the index key this contains a reference to
- the <quote>operator class</quote> to use. See
+ the operator class to use. See
<structname>pg_opclass</structname> for details.
</entry>
</row>
<row>
- <entry>indisclustered</entry>
+ <entry><structfield>indisclustered</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>If true, the table was last clustered on this index.</entry>
</row>
<row>
- <entry>indisunique</entry>
+ <entry><structfield>indisunique</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>If true, this is a unique index.</entry>
</row>
<row>
- <entry>indisprimary</entry>
+ <entry><structfield>indisprimary</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>If true, this index represents the primary key of the table.
- (indisunique should always be true when this is true.)</entry>
+ (<structfield>indisunique</> should always be true when this is true.)</entry>
</row>
<row>
- <entry>indreference</entry>
+ <entry><structfield>indreference</structfield></entry>
<entry><type>oid</type></entry>
<entry></entry>
<entry>unused</entry>
</row>
<row>
- <entry>indpred</entry>
+ <entry><structfield>indpred</structfield></entry>
<entry><type>text</type></entry>
<entry></entry>
- <entry>Expression tree (in the form of a nodeToString representation)
+ <entry>Expression tree (in the form of a <function>nodeToString()</function> representation)
for partial index predicate. Empty string if not a partial
index.</entry>
</row>
<sect1 id="catalog-pg-inherits">
- <title>pg_inherits</title>
+ <title><structname>pg_inherits</structname></title>
+
+ <indexterm zone="catalog-pg-inherits">
+ <primary>pg_inherits</primary>
+ </indexterm>
<para>
- This catalog records information about table inheritance hierarchies.
+ The catalog <structname>pg_inherits</> records information about
+ table inheritance hierarchies.
</para>
<table>
- <title>pg_inherits Columns</title>
+ <title><structname>pg_inherits</> Columns</title>
<tgroup cols=4>
<thead>
<tbody>
<row>
- <entry>inhrelid</entry>
+ <entry><structfield>inhrelid</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_class.oid</entry>
+ <entry><literal>pg_class.oid</literal></entry>
<entry>
The OID of the child table.
</entry>
</row>
<row>
- <entry>inhparent</entry>
+ <entry><structfield>inhparent</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_class.oid</entry>
+ <entry><literal>pg_class.oid</literal></entry>
<entry>
The OID of the parent table.
</entry>
</row>
<row>
- <entry>inhseqno</entry>
+ <entry><structfield>inhseqno</structfield></entry>
<entry><type>int4</type></entry>
<entry></entry>
<entry>
<sect1 id="catalog-pg-language">
- <title>pg_language</title>
+ <title><structname>pg_language</structname></title>
+
+ <indexterm zone="catalog-pg-language">
+ <primary>pg_language</primary>
+ </indexterm>
<para>
- <structname>pg_language</structname> registers call interfaces or
+ The catalog <structname>pg_language</structname> registers call interfaces or
languages in which you can write functions or stored procedures.
See under <command>CREATE LANGUAGE</command> and in
- <xref linkend="server-programming"> for more information about language handlers.
+ <xref linkend="xplang"> for more information about language handlers.
</para>
<table>
- <title>pg_language Columns</title>
+ <title><structname>pg_language</> Columns</title>
<tgroup cols=4>
<thead>
<tbody>
<row>
- <entry>lanname</entry>
+ <entry><structfield>lanname</structfield></entry>
<entry><type>name</type></entry>
<entry></entry>
<entry>Name of the language (to be specified when creating a function)</entry>
</row>
<row>
- <entry>lanispl</entry>
+ <entry><structfield>lanispl</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>
</row>
<row>
- <entry>lanpltrusted</entry>
+ <entry><structfield>lanpltrusted</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>
This is a trusted language. See under <command>CREATE
LANGUAGE</command> what this means. If this is an internal
language (<structfield>lanispl</structfield> is false) then
- this field is meaningless.
+ this column is meaningless.
</entry>
</row>
<row>
- <entry>lanplcallfoid</entry>
+ <entry><structfield>lanplcallfoid</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_proc.oid</entry>
+ <entry><literal>pg_proc.oid</literal></entry>
<entry>
- For non-internal languages this references the language
+ For noninternal languages this references the language
handler, which is a special function that is responsible for
executing all functions that are written in the particular
language.
</row>
<row>
- <entry>lanvalidator</entry>
+ <entry><structfield>lanvalidator</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_proc.oid</entry>
+ <entry><literal>pg_proc.oid</literal></entry>
<entry>
This references a language validator function that is responsible
for checking the syntax and validity of new functions when they
</row>
<row>
- <entry>lanacl</entry>
+ <entry><structfield>lanacl</structfield></entry>
<entry><type>aclitem[]</type></entry>
<entry></entry>
- <entry>Access permissions</entry>
+ <entry>Access privileges</entry>
</row>
</tbody>
</tgroup>
<sect1 id="catalog-pg-largeobject">
- <title>pg_largeobject</title>
+ <title><structname>pg_largeobject</structname></title>
+
+ <indexterm zone="catalog-pg-largeobject">
+ <primary>pg_largeobject</primary>
+ </indexterm>
<para>
- <structname>pg_largeobject</structname> holds the data making up
+ The catalog <structname>pg_largeobject</structname> holds the data making up
<quote>large objects</quote>. A large object is identified by an
OID assigned when it is created. Each large object is broken into
segments or <quote>pages</> small enough to be conveniently stored as rows
in <structname>pg_largeobject</structname>.
- The amount of data per page is defined to be LOBLKSIZE (which is currently
- BLCKSZ/4, or typically 2Kbytes).
+ The amount of data per page is defined to be <literal>LOBLKSIZE</> (which is currently
+ <literal>BLCKSZ/4</>, or typically 2 kB).
</para>
<table>
- <title>pg_largeobject Columns</title>
+ <title><structname>pg_largeobject</> Columns</title>
<tgroup cols=4>
<thead>
<tbody>
<row>
- <entry>loid</entry>
+ <entry><structfield>loid</structfield></entry>
<entry><type>oid</type></entry>
<entry></entry>
<entry>Identifier of the large object that includes this page</entry>
</row>
<row>
- <entry>pageno</entry>
+ <entry><structfield>pageno</structfield></entry>
<entry><type>int4</type></entry>
<entry></entry>
<entry>Page number of this page within its large object
</row>
<row>
- <entry>data</entry>
+ <entry><structfield>data</structfield></entry>
<entry><type>bytea</type></entry>
<entry></entry>
<entry>
Actual data stored in the large object.
- This will never be more than LOBLKSIZE bytes, and may be less.
+ This will never be more than <symbol>LOBLKSIZE</> bytes and may be less.
</entry>
</row>
</tbody>
<para>
Each row of <structname>pg_largeobject</structname> holds data
for one page of a large object, beginning at
- byte offset (pageno * LOBLKSIZE) within the object. The implementation
+ byte offset (<literal>pageno * LOBLKSIZE</>) within the object. The implementation
allows sparse storage: pages may be missing, and may be shorter than
- LOBLKSIZE bytes even if they are not the last page of the object.
+ <literal>LOBLKSIZE</> bytes even if they are not the last page of the object.
Missing regions within a large object read as zeroes.
</para>
<sect1 id="catalog-pg-listener">
- <title>pg_listener</title>
+ <title><structname>pg_listener</structname></title>
+
+ <indexterm zone="catalog-pg-listener">
+ <primary>pg_listener</primary>
+ </indexterm>
<para>
- <structname>pg_listener</structname> supports the <command>LISTEN</>
+ The catalog <structname>pg_listener</structname> supports the <command>LISTEN</>
and <command>NOTIFY</> commands. A listener creates an entry in
<structname>pg_listener</structname> for each notification name
it is listening for. A notifier scans <structname>pg_listener</structname>
</para>
<table>
- <title>pg_listener Columns</title>
+ <title><structname>pg_listener</> Columns</title>
<tgroup cols=4>
<thead>
<tbody>
<row>
- <entry>relname</entry>
+ <entry><structfield>relname</structfield></entry>
<entry><type>name</type></entry>
<entry></entry>
<entry>Notify condition name. (The name need not match any actual
- relation in the database; the term <quote>relname</> is historical.)
+ relation in the database; the name <structfield>relname</> is historical.)
</entry>
</row>
<row>
- <entry>listenerpid</entry>
+ <entry><structfield>listenerpid</structfield></entry>
<entry><type>int4</type></entry>
<entry></entry>
- <entry>PID of the backend process that created this entry.</entry>
+ <entry>PID of the server process that created this entry.</entry>
</row>
<row>
- <entry>notification</entry>
+ <entry><structfield>notification</structfield></entry>
<entry><type>int4</type></entry>
<entry></entry>
<entry>
Zero if no event is pending for this listener. If an event is
- pending, the PID of the backend that sent the notification.
+ pending, the PID of the server process that sent the notification.
</entry>
</row>
</tbody>
<sect1 id="catalog-pg-namespace">
- <title>pg_namespace</title>
+ <title><structname>pg_namespace</structname></title>
+
+ <indexterm zone="catalog-pg-namespace">
+ <primary>pg_namespace</primary>
+ </indexterm>
<para>
- A namespace is the structure underlying SQL92 schemas: each namespace
- can have a separate collection of relations, types, etc without name
+ The catalog <structname>pg_namespace</> stores namespaces.
+ A namespace is the structure underlying SQL schemas: each namespace
+ can have a separate collection of relations, types, etc. without name
conflicts.
</para>
<table>
- <title>pg_namespace Columns</title>
+ <title><structname>pg_namespace</> Columns</title>
<tgroup cols=4>
<thead>
<tbody>
<row>
- <entry>nspname</entry>
+ <entry><structfield>nspname</structfield></entry>
<entry><type>name</type></entry>
<entry></entry>
<entry>Name of the namespace</entry>
</row>
<row>
- <entry>nspowner</entry>
+ <entry><structfield>nspowner</structfield></entry>
<entry><type>int4</type></entry>
- <entry>pg_shadow.usesysid</entry>
- <entry>Owner (creator) of the namespace</entry>
+ <entry><literal>pg_shadow.usesysid</literal></entry>
+ <entry>Owner of the namespace</entry>
</row>
<row>
- <entry>nspacl</entry>
+ <entry><structfield>nspacl</structfield></entry>
<entry><type>aclitem[]</type></entry>
<entry></entry>
- <entry>Access permissions</entry>
+ <entry>Access privileges</entry>
</row>
</tbody>
</tgroup>
<sect1 id="catalog-pg-opclass">
- <title>pg_opclass</title>
+ <title><structname>pg_opclass</structname></title>
+
+ <indexterm zone="catalog-pg-opclass">
+ <primary>pg_opclass</primary>
+ </indexterm>
<para>
- <structname>pg_opclass</structname> defines
+ The catalog <structname>pg_opclass</structname> defines
index access method operator classes. Each operator class defines
- semantics for index columns of a particular datatype and a particular
+ semantics for index columns of a particular data type and a particular
index access method. Note that there can be multiple operator classes
- for a given datatype/access method combination, thus supporting multiple
+ for a given data type/access method combination, thus supporting multiple
behaviors.
</para>
<para>
- Operator classes are described at length in <xref linkend="server-programming">.
+ Operator classes are described at length in <xref linkend="xindex">.
</para>
<table>
- <title>pg_opclass Columns</title>
+ <title><structname>pg_opclass</> Columns</title>
<tgroup cols=4>
<thead>
<tbody>
<row>
- <entry>opcamid</entry>
+ <entry><structfield>opcamid</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_am.oid</entry>
- <entry>index access method opclass is for</entry>
+ <entry><literal>pg_am.oid</literal></entry>
+ <entry>Index access method opclass is for</entry>
</row>
<row>
- <entry>opcname</entry>
+ <entry><structfield>opcname</structfield></entry>
<entry><type>name</type></entry>
<entry></entry>
- <entry>name of this opclass</entry>
+ <entry>Name of this operator class</entry>
</row>
<row>
- <entry>opcnamespace</entry>
+ <entry><structfield>opcnamespace</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_namespace.oid</entry>
- <entry>namespace of this opclass</entry>
+ <entry><literal>pg_namespace.oid</literal></entry>
+ <entry>Namespace of this operator class</entry>
</row>
<row>
- <entry>opcowner</entry>
+ <entry><structfield>opcowner</structfield></entry>
<entry><type>int4</type></entry>
- <entry>pg_shadow.usesysid</entry>
- <entry>opclass owner</entry>
+ <entry><literal>pg_shadow.usesysid</literal></entry>
+ <entry>Operator class owner</entry>
</row>
<row>
- <entry>opcintype</entry>
+ <entry><structfield>opcintype</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_type.oid</entry>
- <entry>type of input data for opclass</entry>
+ <entry><literal>pg_type.oid</literal></entry>
+ <entry>Input data type of the operator class</entry>
</row>
<row>
- <entry>opcdefault</entry>
+ <entry><structfield>opcdefault</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
- <entry>true if opclass is default for opcintype</entry>
+ <entry>True if this operator class is the default for <structfield>opcintype</></entry>
</row>
<row>
- <entry>opckeytype</entry>
+ <entry><structfield>opckeytype</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_type.oid</entry>
- <entry>type of index data, or zero if same as opcintype</entry>
+ <entry><literal>pg_type.oid</literal></entry>
+ <entry>Type of index data, or zero if same as <structfield>opcintype</></entry>
</row>
</tbody>
<structname>pg_amproc</structname>. Those rows are considered to be
part of the operator class definition --- this is not unlike the way
that a relation is defined by a single <structname>pg_class</structname>
- row, plus associated rows in <structname>pg_attribute</structname> and
+ row plus associated rows in <structname>pg_attribute</structname> and
other tables.
</para>
<sect1 id="catalog-pg-operator">
- <title>pg_operator</title>
+ <title><structname>pg_operator</structname></title>
+
+ <indexterm zone="catalog-pg-operator">
+ <primary>pg_operator</primary>
+ </indexterm>
<para>
- See <command>CREATE OPERATOR</command> and <xref linkend="xoper">
- for details on these operator parameters.
+ The catalog <structname>pg_operator</> stores information about operators. See
+ <command>CREATE OPERATOR</command> and <xref linkend="xoper"> for
+ details on these operator parameters.
</para>
<table>
- <title>pg_operator Columns</title>
+ <title><structname>pg_operator</> Columns</title>
<tgroup cols=4>
<thead>
<tbody>
<row>
- <entry>oprname</entry>
+ <entry><structfield>oprname</structfield></entry>
<entry><type>name</type></entry>
<entry></entry>
<entry>Name of the operator</entry>
</row>
<row>
- <entry>oprnamespace</entry>
+ <entry><structfield>oprnamespace</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_namespace.oid</entry>
+ <entry><literal>pg_namespace.oid</literal></entry>
<entry>
The OID of the namespace that contains this operator
</entry>
</row>
<row>
- <entry>oprowner</entry>
+ <entry><structfield>oprowner</structfield></entry>
<entry><type>int4</type></entry>
- <entry>pg_shadow.usesysid</entry>
- <entry>Owner (creator) of the operator</entry>
+ <entry><literal>pg_shadow.usesysid</literal></entry>
+ <entry>Owner of the operator</entry>
</row>
<row>
- <entry>oprkind</entry>
+ <entry><structfield>oprkind</structfield></entry>
<entry><type>char</type></entry>
<entry></entry>
<entry>
- 'b' = infix (<quote>both</quote>), 'l' = prefix
- (<quote>left</quote>), 'r' = postfix (<quote>right</quote>)
+ <literal>b</> = infix (<quote>both</quote>), <literal>l</> = prefix
+ (<quote>left</quote>), <literal>r</> = postfix (<quote>right</quote>)
</entry>
</row>
<row>
- <entry>oprcanhash</entry>
+ <entry><structfield>oprcanhash</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>This operator supports hash joins.</entry>
</row>
<row>
- <entry>oprleft</entry>
+ <entry><structfield>oprleft</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_type.oid</entry>
+ <entry><literal>pg_type.oid</literal></entry>
<entry>Type of the left operand</entry>
</row>
<row>
- <entry>oprright</entry>
+ <entry><structfield>oprright</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_type.oid</entry>
+ <entry><literal>pg_type.oid</literal></entry>
<entry>Type of the right operand</entry>
</row>
<row>
- <entry>oprresult</entry>
+ <entry><structfield>oprresult</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_type.oid</entry>
+ <entry><literal>pg_type.oid</literal></entry>
<entry>Type of the result</entry>
</row>
<row>
- <entry>oprcom</entry>
+ <entry><structfield>oprcom</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_operator.oid</entry>
+ <entry><literal>pg_operator.oid</literal></entry>
<entry>Commutator of this operator, if any</entry>
</row>
<row>
- <entry>oprnegate</entry>
+ <entry><structfield>oprnegate</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_operator.oid</entry>
+ <entry><literal>pg_operator.oid</literal></entry>
<entry>Negator of this operator, if any</entry>
</row>
<row>
- <entry>oprlsortop</entry>
+ <entry><structfield>oprlsortop</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_operator.oid</entry>
+ <entry><literal>pg_operator.oid</literal></entry>
<entry>
If this operator supports merge joins, the operator that sorts
the type of the left-hand operand (<literal>L<L</>)
</row>
<row>
- <entry>oprrsortop</entry>
+ <entry><structfield>oprrsortop</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_operator.oid</entry>
+ <entry><literal>pg_operator.oid</literal></entry>
<entry>
If this operator supports merge joins, the operator that sorts
the type of the right-hand operand (<literal>R<R</>)
</row>
<row>
- <entry>oprltcmpop</entry>
+ <entry><structfield>oprltcmpop</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_operator.oid</entry>
+ <entry><literal>pg_operator.oid</literal></entry>
<entry>
If this operator supports merge joins, the less-than operator that
compares the left and right operand types (<literal>L<R</>)
</row>
<row>
- <entry>oprgtcmpop</entry>
+ <entry><structfield>oprgtcmpop</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_operator.oid</entry>
+ <entry><literal>pg_operator.oid</literal></entry>
<entry>
If this operator supports merge joins, the greater-than operator that
compares the left and right operand types (<literal>L>R</>)
</row>
<row>
- <entry>oprcode</entry>
+ <entry><structfield>oprcode</structfield></entry>
<entry><type>regproc</type></entry>
- <entry>pg_proc.oid</entry>
+ <entry><literal>pg_proc.oid</literal></entry>
<entry>Function that implements this operator</entry>
</row>
<row>
- <entry>oprrest</entry>
+ <entry><structfield>oprrest</structfield></entry>
<entry><type>regproc</type></entry>
- <entry>pg_proc.oid</entry>
+ <entry><literal>pg_proc.oid</literal></entry>
<entry>Restriction selectivity estimation function for this operator</entry>
</row>
<row>
- <entry>oprjoin</entry>
+ <entry><structfield>oprjoin</structfield></entry>
<entry><type>regproc</type></entry>
- <entry>pg_proc.oid</entry>
+ <entry><literal>pg_proc.oid</literal></entry>
<entry>Join selectivity estimation function for this operator</entry>
</row>
</tbody>
</table>
<para>
- Unused fields contain zeroes, for example oprleft is zero for a
+ Unused column contain zeroes, for example <structfield>oprleft</structfield> is zero for a
prefix operator.
</para>
<sect1 id="catalog-pg-proc">
- <title>pg_proc</title>
+ <title><structname>pg_proc</structname></title>
+
+ <indexterm zone="catalog-pg-proc">
+ <primary>pg_proc</primary>
+ </indexterm>
<para>
- This catalog stores information about functions (or procedures).
+ The catalog <structname>pg_proc</> stores information about functions (or procedures).
The description of <command>CREATE FUNCTION</command> and
<xref linkend="xfunc"> contain more information about the meaning of
- some fields.
+ some columns.
</para>
<para>
The table contains data for aggregate functions as well as plain functions.
If <structfield>proisagg</structfield> is true, there should be a matching
- row in <structname>pg_aggregate</structname>.
+ row in <structfield>pg_aggregate</structfield>.
</para>
<table>
- <title>pg_proc Columns</title>
+ <title><structname>pg_proc</> Columns</title>
<tgroup cols=4>
<thead>
<tbody>
<row>
- <entry>proname</entry>
+ <entry><structfield>proname</structfield></entry>
<entry><type>name</type></entry>
<entry></entry>
<entry>Name of the function</entry>
</row>
<row>
- <entry>pronamespace</entry>
+ <entry><structfield>pronamespace</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_namespace.oid</entry>
+ <entry><literal>pg_namespace.oid</literal></entry>
<entry>
The OID of the namespace that contains this function
</entry>
</row>
<row>
- <entry>proowner</entry>
+ <entry><structfield>proowner</structfield></entry>
<entry><type>int4</type></entry>
- <entry>pg_shadow.usesysid</entry>
- <entry>Owner (creator) of the function</entry>
+ <entry><literal>pg_shadow.usesysid</literal></entry>
+ <entry>Owner of the function</entry>
</row>
<row>
- <entry>prolang</entry>
+ <entry><structfield>prolang</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_language.oid</entry>
+ <entry><literal>pg_language.oid</literal></entry>
<entry>Implementation language or call interface of this function</entry>
</row>
<row>
- <entry>proisagg</entry>
+ <entry><structfield>proisagg</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>Function is an aggregate function</entry>
</row>
<row>
- <entry>prosecdef</entry>
+ <entry><structfield>prosecdef</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>Function is a security definer (i.e., a <quote>setuid</>
</row>
<row>
- <entry>proisstrict</entry>
+ <entry><structfield>proisstrict</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>
</row>
<row>
- <entry>proretset</entry>
+ <entry><structfield>proretset</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
- <entry>Function returns a set (ie, multiple values of the specified
+ <entry>Function returns a set (i.e., multiple values of the specified
data type)</entry>
</row>
<row>
- <entry>provolatile</entry>
+ <entry><structfield>provolatile</structfield></entry>
<entry><type>char</type></entry>
<entry></entry>
<entry>
</row>
<row>
- <entry>pronargs</entry>
+ <entry><structfield>pronargs</structfield></entry>
<entry><type>int2</type></entry>
<entry></entry>
<entry>Number of arguments</entry>
</row>
<row>
- <entry>prorettype</entry>
+ <entry><structfield>prorettype</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_type.oid</entry>
+ <entry><literal>pg_type.oid</literal></entry>
<entry>Data type of the return value</entry>
</row>
<row>
- <entry>proargtypes</entry>
+ <entry><structfield>proargtypes</structfield></entry>
<entry><type>oidvector</type></entry>
- <entry>pg_type.oid</entry>
- <entry>A vector with the data types of the function arguments</entry>
+ <entry><literal>pg_type.oid</literal></entry>
+ <entry>An array with the data types of the function arguments</entry>
</row>
<row>
- <entry>prosrc</entry>
+ <entry><structfield>prosrc</structfield></entry>
<entry><type>text</type></entry>
<entry></entry>
<entry>
</row>
<row>
- <entry>probin</entry>
+ <entry><structfield>probin</structfield></entry>
<entry><type>bytea</type></entry>
<entry></entry>
<entry>Additional information about how to invoke the function.
</row>
<row>
- <entry>proacl</entry>
+ <entry><structfield>proacl</structfield></entry>
<entry><type>aclitem[]</type></entry>
<entry></entry>
- <entry>Access permissions</entry>
+ <entry>Access privileges</entry>
</row>
</tbody>
</tgroup>
</table>
<para>
- Currently, prosrc contains the function's C-language name (link symbol)
- for compiled functions, both built-in and dynamically loaded. For all
- other language types, prosrc contains the function's source text.
- </para>
-
- <para>
- Currently, probin is unused except for dynamically-loaded C functions,
- for which it gives the name of the shared library file containing the
- function.
+ <structfield>prosrc</structfield> contains the function's C-language
+ name (link symbol) for compiled functions, both built-in and
+ dynamically loaded. For all other language types,
+ <structfield>prosrc</structfield> contains the function's source
+ text. <structfield>probin</structfield> is unused except for
+ dynamically-loaded C functions, for which it gives the name of the
+ shared library file containing the function.
</para>
</sect1>
<sect1 id="catalog-pg-rewrite">
- <title>pg_rewrite</title>
+ <title><structname>pg_rewrite</structname></title>
+
+ <indexterm zone="catalog-pg-rewrite">
+ <primary>pg_rewrite</primary>
+ </indexterm>
<para>
- This system catalog stores rewrite rules for tables and views.
+ The catalog <structname>pg_rewrite</structname> stores rewrite rules for tables and views.
</para>
<table>
- <title>pg_rewrite Columns</title>
+ <title><structname>pg_rewrite</> Columns</title>
<tgroup cols=4>
<thead>
<tbody>
<row>
- <entry>rulename</entry>
+ <entry><structfield>rulename</structfield></entry>
<entry><type>name</type></entry>
<entry></entry>
<entry>Rule name</entry>
</row>
<row>
- <entry>ev_class</entry>
+ <entry><structfield>ev_class</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_class.oid</entry>
+ <entry><literal>pg_class.oid</literal></entry>
<entry>The table this rule is for</entry>
</row>
<row>
- <entry>ev_attr</entry>
+ <entry><structfield>ev_attr</structfield></entry>
<entry><type>int2</type></entry>
<entry></entry>
<entry>The column this rule is for (currently, always zero to
</row>
<row>
- <entry>ev_type</entry>
+ <entry><structfield>ev_type</structfield></entry>
<entry><type>char</type></entry>
<entry></entry>
- <entry>Event type that the rule is for: '1' = SELECT,
- '2' = UPDATE, '3' = INSERT, '4' = DELETE</entry>
+ <entry>
+ Event type that the rule is for: 1 = <command>SELECT</>, 2 =
+ <command>UPDATE</>, 3 = <command>INSERT</>, 4 =
+ <command>DELETE</>
+ </entry>
</row>
<row>
- <entry>is_instead</entry>
+ <entry><structfield>is_instead</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
- <entry>True if the rule is an INSTEAD rule</entry>
+ <entry>True if the rule is an <literal>INSTEAD</literal> rule</entry>
</row>
<row>
- <entry>ev_qual</entry>
+ <entry><structfield>ev_qual</structfield></entry>
<entry><type>text</type></entry>
<entry></entry>
- <entry>Expression tree (in the form of a nodeToString representation)
- for the rule's qualifying condition</entry>
+ <entry>
+ Expression tree (in the form of a
+ <function>nodeToString()</function> representation) for the
+ rule's qualifying condition
+ </entry>
</row>
<row>
- <entry>ev_action</entry>
+ <entry><structfield>ev_action</structfield></entry>
<entry><type>text</type></entry>
<entry></entry>
- <entry>Query tree (in the form of a nodeToString representation)
- for the rule's action</entry>
+ <entry>
+ Query tree (in the form of a
+ <function>nodeToString()</function> representation) for the
+ rule's action
+ </entry>
</row>
</tbody>
</tgroup>
<note>
<para>
- <structname>pg_class</structname>.<structfield>relhasrules</structfield>
+ <literal>pg_class.relhasrules</literal>
must be true if a table has any rules in this catalog.
</para>
</note>
<sect1 id="catalog-pg-shadow">
- <title>pg_shadow</title>
+ <title><structname>pg_shadow</structname></title>
+
+ <indexterm zone="catalog-pg-shadow">
+ <primary>pg_shadow</primary>
+ </indexterm>
<para>
- <structname>pg_shadow</structname> contains information about
+ The catalog <structname>pg_shadow</structname> contains information about
database users. The name stems from the fact that this table
should not be readable by the public since it contains passwords.
- <structname>pg_user</structname> is a publicly readable view on
- <structname>pg_shadow</structname> that blanks out the password field.
+ <structfield>pg_user</structfield> is a publicly readable view on
+ <structfield>pg_shadow</structfield> that blanks out the password field.
</para>
<para>
<xref linkend="user-manag"> contains detailed information about user and
- permission management.
+ privilege management.
</para>
<para>
</para>
<table>
- <title>pg_shadow Columns</title>
+ <title><structname>pg_shadow</> Columns</title>
<tgroup cols=4>
<thead>
<tbody>
<row>
- <entry>usename</entry>
+ <entry><structfield>usename</structfield></entry>
<entry><type>name</type></entry>
<entry></entry>
<entry>User name</entry>
</row>
<row>
- <entry>usesysid</entry>
+ <entry><structfield>usesysid</structfield></entry>
<entry><type>int4</type></entry>
<entry></entry>
<entry>User id (arbitrary number used to reference this user)</entry>
</row>
<row>
- <entry>usecreatedb</entry>
+ <entry><structfield>usecreatedb</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>User may create databases</entry>
</row>
<row>
- <entry>usesuper</entry>
+ <entry><structfield>usesuper</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>User is a superuser</entry>
</row>
<row>
- <entry>usecatupd</entry>
+ <entry><structfield>usecatupd</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>
User may update system catalogs. (Even a superuser may not do
- this unless this attribute is true.)
+ this unless this column is true.)
</entry>
</row>
<row>
- <entry>passwd</entry>
+ <entry><structfield>passwd</structfield></entry>
<entry><type>text</type></entry>
<entry></entry>
<entry>Password</entry>
</row>
<row>
- <entry>valuntil</entry>
+ <entry><structfield>valuntil</structfield></entry>
<entry><type>abstime</type></entry>
<entry></entry>
<entry>Account expiry time (only used for password authentication)</entry>
</row>
<row>
- <entry>useconfig</entry>
+ <entry><structfield>useconfig</structfield></entry>
<entry><type>text[]</type></entry>
<entry></entry>
<entry>Session defaults for run-time configuration variables</entry>
<sect1 id="catalog-pg-statistic">
- <title>pg_statistic</title>
+ <title><structname>pg_statistic</structname></title>
+
+ <indexterm zone="catalog-pg-statistic">
+ <primary>pg_statistic</primary>
+ </indexterm>
<para>
- <structname>pg_statistic</structname> stores statistical data about
+ The catalog <structname>pg_statistic</structname> stores statistical data about
the contents of the database. Entries are created by
<command>ANALYZE</command> and subsequently used by the query planner.
There is one entry for each table column that has been analyzed.
Since different kinds of statistics may be appropriate for different
kinds of data, <structname>pg_statistic</structname> is designed not
to assume very much about what sort of statistics it stores. Only
- extremely general statistics (such as NULL-ness) are given dedicated
+ extremely general statistics (such as nullness) are given dedicated
columns in <structname>pg_statistic</structname>. Everything else
is stored in <quote>slots</quote>, which are groups of associated columns whose
content is identified by a code number in one of the slot's columns.
</para>
<table>
- <title>pg_statistic Columns</title>
+ <title><structname>pg_statistic</> Columns</title>
<tgroup cols=4>
<thead>
<tbody>
<row>
- <entry>starelid</entry>
+ <entry><structfield>starelid</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_class.oid</entry>
+ <entry><literal>pg_class.oid</literal></entry>
<entry>The table that the described column belongs to</entry>
</row>
<row>
- <entry>staattnum</entry>
+ <entry><structfield>staattnum</structfield></entry>
<entry><type>int2</type></entry>
- <entry>pg_attribute.attnum</entry>
+ <entry><literal>pg_attribute.attnum</literal></entry>
<entry>The number of the described column</entry>
</row>
<row>
- <entry>stanullfrac</entry>
+ <entry><structfield>stanullfrac</structfield></entry>
<entry><type>float4</type></entry>
<entry></entry>
- <entry>The fraction of the column's entries that are NULL</entry>
+ <entry>The fraction of the column's entries that are null</entry>
</row>
<row>
- <entry>stawidth</entry>
+ <entry><structfield>stawidth</structfield></entry>
<entry><type>int4</type></entry>
<entry></entry>
- <entry>The average stored width, in bytes, of non-NULL entries</entry>
+ <entry>The average stored width, in bytes, of nonnull entries</entry>
</row>
<row>
- <entry>stadistinct</entry>
+ <entry><structfield>stadistinct</structfield></entry>
<entry><type>float4</type></entry>
<entry></entry>
- <entry>The number of distinct non-NULL data values in the column.
+ <entry>The number of distinct nonnull data values in the column.
A value greater than zero is the actual number of distinct values.
A value less than zero is the negative of a fraction of the number
of rows in the table (for example, a column in which values appear about
- twice on the average could be represented by stadistinct = -0.5).
+ twice on the average could be represented by <structfield>stadistinct</> = -0.5).
A zero value means the number of distinct values is unknown.
</entry>
</row>
<row>
- <entry>stakindN</entry>
+ <entry><structfield>stakind<replaceable>N</></structfield></entry>
<entry><type>int2</type></entry>
<entry></entry>
- <entry>A code number indicating the kind of statistics stored in the Nth
- <quote>slot</quote> of the <structname>pg_statistic</structname> row.
+ <entry>
+ A code number indicating the kind of statistics stored in the
+ <replaceable>N</>th <quote>slot</quote> of the
+ <structname>pg_statistic</structname> row.
</entry>
</row>
<row>
- <entry>staopN</entry>
+ <entry><structfield>staop<replaceable>N</></structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_operator.oid</entry>
- <entry>An operator used to derive the statistics stored in the
- Nth <quote>slot</quote>. For example, a histogram slot would show the <literal><</literal>
- operator that defines the sort order of the data.
+ <entry><literal>pg_operator.oid</literal></entry>
+ <entry>
+ An operator used to derive the statistics stored in the
+ <replaceable>N</>th <quote>slot</quote>. For example, a
+ histogram slot would show the <literal><</literal> operator
+ that defines the sort order of the data.
</entry>
</row>
<row>
- <entry>stanumbersN</entry>
+ <entry><structfield>stanumbers<replaceable>N</></structfield></entry>
<entry><type>float4[]</type></entry>
<entry></entry>
- <entry>Numerical statistics of the appropriate kind for the Nth
- <quote>slot</quote>, or NULL if the slot kind does not involve numerical values.
+ <entry>
+ Numerical statistics of the appropriate kind for the
+ <replaceable>N</>th <quote>slot</quote>, or null if the slot
+ kind does not involve numerical values.
</entry>
</row>
<row>
- <entry>stavaluesN</entry>
+ <entry><structfield>stavalues<replaceable>N</></structfield></entry>
<entry><type>anyarray</type></entry>
<entry></entry>
- <entry>Column data values of the appropriate kind for the Nth
- <quote>slot</quote>, or NULL if the slot kind does not store any data
- values.
- Each array's element values are actually of the specific column's
- datatype, so there is no way to define these columns' type more
- specifically than <quote>anyarray</>.
+ <entry>
+ Column data values of the appropriate kind for the
+ <replaceable>N</>th <quote>slot</quote>, or null if the slot
+ kind does not store any data values. Each array's element
+ values are actually of the specific column's data type, so there
+ is no way to define these columns' type more specifically than
+ <type>anyarray</>.
</entry>
</row>
</tbody>
<sect1 id="catalog-pg-trigger">
- <title>pg_trigger</title>
+ <title><structname>pg_trigger</structname></title>
+
+ <indexterm zone="catalog-pg-trigger">
+ <primary>pg_trigger</primary>
+ </indexterm>
<para>
- This system catalog stores triggers on tables. See under
+ The catalog <structname>pg_trigger</structname> stores triggers on tables. See under
<command>CREATE TRIGGER</command> for more information.
</para>
<table>
- <title>pg_trigger Columns</title>
+ <title><structname>pg_trigger</> Columns</title>
<tgroup cols=4>
<thead>
<tbody>
<row>
- <entry>tgrelid</entry>
+ <entry><structfield>tgrelid</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_class.oid</entry>
+ <entry><literal>pg_class.oid</literal></entry>
<entry>The table this trigger is on</entry>
</row>
<row>
- <entry>tgname</entry>
+ <entry><structfield>tgname</structfield></entry>
<entry><type>name</type></entry>
<entry></entry>
<entry>Trigger name (must be unique among triggers of same table)</entry>
</row>
<row>
- <entry>tgfoid</entry>
+ <entry><structfield>tgfoid</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_proc.oid</entry>
+ <entry><literal>pg_proc.oid</literal></entry>
<entry>The function to be called</entry>
</row>
<row>
- <entry>tgtype</entry>
+ <entry><structfield>tgtype</structfield></entry>
<entry><type>int2</type></entry>
<entry></entry>
<entry>Bitmask identifying trigger conditions</entry>
</row>
<row>
- <entry>tgenabled</entry>
+ <entry><structfield>tgenabled</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>True if trigger is enabled (not presently checked everywhere
</row>
<row>
- <entry>tgisconstraint</entry>
+ <entry><structfield>tgisconstraint</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
- <entry>True if trigger implements an RI constraint</entry>
+ <entry>True if trigger implements a referential integrity constraint</entry>
</row>
<row>
- <entry>tgconstrname</entry>
+ <entry><structfield>tgconstrname</structfield></entry>
<entry><type>name</type></entry>
<entry></entry>
- <entry>RI constraint name</entry>
+ <entry>Referential integrity constraint name</entry>
</row>
<row>
- <entry>tgconstrrelid</entry>
+ <entry><structfield>tgconstrrelid</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_class.oid</entry>
- <entry>The table referenced by an RI constraint</entry>
+ <entry><literal>pg_class.oid</literal></entry>
+ <entry>The table referenced by an referential integrity constraint</entry>
</row>
<row>
- <entry>tgdeferrable</entry>
+ <entry><structfield>tgdeferrable</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>True if deferrable</entry>
</row>
<row>
- <entry>tginitdeferred</entry>
+ <entry><structfield>tginitdeferred</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>True if initially deferred</entry>
</row>
<row>
- <entry>tgnargs</entry>
+ <entry><structfield>tgnargs</structfield></entry>
<entry><type>int2</type></entry>
<entry></entry>
<entry>Number of argument strings passed to trigger function</entry>
</row>
<row>
- <entry>tgattr</entry>
+ <entry><structfield>tgattr</structfield></entry>
<entry><type>int2vector</type></entry>
<entry></entry>
<entry>Currently unused</entry>
</row>
<row>
- <entry>tgargs</entry>
+ <entry><structfield>tgargs</structfield></entry>
<entry><type>bytea</type></entry>
<entry></entry>
<entry>Argument strings to pass to trigger, each null-terminated</entry>
<note>
<para>
- <structname>pg_class</structname>.<structfield>reltriggers</structfield>
- needs to match up with the entries in this table.
+ <literal>pg_class.reltriggers</literal> needs to match up with the
+ entries in this table.
</para>
</note>
<sect1 id="catalog-pg-type">
- <title>pg_type</title>
+ <title><structname>pg_type</structname></title>
+
+ <indexterm zone="catalog-pg-type">
+ <primary>pg_type</primary>
+ </indexterm>
<para>
- This catalog stores information about data types. Scalar types
- (<quote>base types</>) are created with <command>CREATE TYPE</command>.
+ The catalog <structname>pg_type</structname> stores information about data types. Base types
+ (scalar types) are created with <command>CREATE TYPE</command>.
A complex type is automatically created for each table in the database, to
represent the row structure of the table. It is also possible to create
- complex types with <command>CREATE TYPE AS</command>, and
+ complex types with <command>CREATE TYPE AS</command> and
derived types with <command>CREATE DOMAIN</command>.
</para>
<table>
- <title>pg_type Columns</title>
+ <title><structname>pg_type</> Columns</title>
<tgroup cols=4>
<thead>
<tbody>
<row>
- <entry>typname</entry>
+ <entry><structfield>typname</structfield></entry>
<entry><type>name</type></entry>
<entry></entry>
<entry>Data type name</entry>
</row>
<row>
- <entry>typnamespace</entry>
+ <entry><structfield>typnamespace</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_namespace.oid</entry>
+ <entry><literal>pg_namespace.oid</literal></entry>
<entry>
The OID of the namespace that contains this type
</entry>
</row>
<row>
- <entry>typowner</entry>
+ <entry><structfield>typowner</structfield></entry>
<entry><type>int4</type></entry>
- <entry>pg_shadow.usesysid</entry>
- <entry>Owner (creator) of the type</entry>
+ <entry><literal>pg_shadow.usesysid</literal></entry>
+ <entry>Owner of the type</entry>
</row>
<row>
- <entry>typlen</entry>
+ <entry><structfield>typlen</structfield></entry>
<entry><type>int2</type></entry>
<entry></entry>
<entry>
</row>
<row>
- <entry>typbyval</entry>
+ <entry><structfield>typbyval</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry>
</row>
<row>
- <entry>typtype</entry>
+ <entry><structfield>typtype</structfield></entry>
<entry><type>char</type></entry>
<entry></entry>
<entry>
</row>
<row>
- <entry>typisdefined</entry>
+ <entry><structfield>typisdefined</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
- <entry>True if the type is defined, false if this is a placeholder
- entry for a not-yet-defined type. When typisdefined is false,
- nothing except the type name, namespace, and OID can be relied on.
+ <entry>
+ True if the type is defined, false if this is a placeholder
+ entry for a not-yet-defined type. When
+ <structfield>typisdefined</structfield> is false, nothing
+ except the type name, namespace, and OID can be relied on.
</entry>
</row>
<row>
- <entry>typdelim</entry>
+ <entry><structfield>typdelim</structfield></entry>
<entry><type>char</type></entry>
<entry></entry>
<entry>Character that separates two values of this type when parsing
</row>
<row>
- <entry>typrelid</entry>
+ <entry><structfield>typrelid</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_class.oid</entry>
+ <entry><literal>pg_class.oid</literal></entry>
<entry>
If this is a complex type (see
- <structfield>typtype</structfield>), then this field points to
+ <structfield>typtype</structfield>), then this column points to
the <structname>pg_class</structname> entry that defines the
corresponding table. (For a free-standing composite type, the
<structname>pg_class</structname> entry doesn't really represent
a table, but it is needed anyway for the type's
<structname>pg_attribute</structname> entries to link to.)
- Zero for non-complex types.
+ Zero for base types.
</entry>
</row>
<row>
- <entry>typelem</entry>
+ <entry><structfield>typelem</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_type.oid</entry>
+ <entry><literal>pg_type.oid</literal></entry>
<entry>
If <structfield>typelem</structfield> is not 0 then it
identifies another row in <structname>pg_type</structname>.
also have nonzero <structfield>typelem</structfield>, for example
<type>name</type> and <type>oidvector</type>.
If a fixed-length type has a <structfield>typelem</structfield> then
- its internal representation must be N values of the
+ its internal representation must be some number of values of the
<structfield>typelem</structfield> data type with no other data.
Variable-length array types have a header defined by the array
subroutines.
</row>
<row>
- <entry>typinput</entry>
+ <entry><structfield>typinput</structfield></entry>
<entry><type>regproc</type></entry>
- <entry>pg_proc.oid</entry>
+ <entry><literal>pg_proc.oid</literal></entry>
<entry>Input conversion function</entry>
</row>
<row>
- <entry>typoutput</entry>
+ <entry><structfield>typoutput</structfield></entry>
<entry><type>regproc</type></entry>
- <entry>pg_proc.oid</entry>
+ <entry><literal>pg_proc.oid</literal></entry>
<entry>Output conversion function</entry>
</row>
<row>
- <entry>typalign</entry>
+ <entry><structfield>typalign</structfield></entry>
<entry><type>char</type></entry>
<entry></entry>
<entry><para>
Possible values are:
<itemizedlist>
<listitem>
- <para>'c' = CHAR alignment, i.e., no alignment needed.</para>
+ <para><literal>c</> = <type>char</type> alignment, i.e., no alignment needed.</para>
</listitem>
<listitem>
- <para>'s' = SHORT alignment (2 bytes on most machines).</para>
+ <para><literal>s</> = <type>short</type> alignment (2 bytes on most machines).</para>
</listitem>
<listitem>
- <para>'i' = INT alignment (4 bytes on most machines).</para>
+ <para><literal>i</> = <type>int</type> alignment (4 bytes on most machines).</para>
</listitem>
<listitem>
- <para>'d' = DOUBLE alignment (8 bytes on many machines, but by no means all).</para>
+ <para><literal>d</> = <type>double</type> alignment (8 bytes on many machines, but by no means all).</para>
</listitem>
</itemizedlist>
</para><note>
<para>
For types used in system tables, it is critical that the size
and alignment defined in <structname>pg_type</structname>
- agree with the way that the compiler will lay out the field in
+ agree with the way that the compiler will lay out the column in
a struct representing a table row.
</para>
</note></entry>
</row>
<row>
- <entry>typstorage</entry>
+ <entry><structfield>typstorage</structfield></entry>
<entry><type>char</type></entry>
<entry></entry>
<entry><para>
Possible values are
<itemizedlist>
<listitem>
- <para>'p': Value must always be stored plain.</para>
+ <para><literal>p</>: Value must always be stored plain.</para>
</listitem>
<listitem>
<para>
- 'e': Value can be stored in a <quote>secondary</quote>
+ <literal>e</>: Value can be stored in a <quote>secondary</quote>
relation (if relation has one, see
- <structname>pg_class</structname>.<structfield>reltoastrelid</structfield>).
+ <literal>pg_class.reltoastrelid</literal>).
</para>
</listitem>
<listitem>
- <para>'m': Value can be stored compressed inline.</para>
+ <para><literal>m</>: Value can be stored compressed inline.</para>
</listitem>
<listitem>
- <para>'x': Value can be stored compressed inline or in <quote>secondary</quote>.</para>
+ <para><literal>x</>: Value can be stored compressed inline or stored in <quote>secondary</quote> storage.</para>
</listitem>
</itemizedlist>
- Note that 'm' fields can also be moved out to secondary
- storage, but only as a last resort ('e' and 'x' fields are
+ Note that <literal>m</> columns can also be moved out to secondary
+ storage, but only as a last resort (<literal>e</> and <literal>x</> columns are
moved first).
</para></entry>
</row>
<row>
- <entry>typnotnull</entry>
+ <entry><structfield>typnotnull</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
<entry><para>
- <structfield>typnotnull</structfield> represents a NOT NULL
- constraint on a type. Presently used for domains only.
+ <structfield>typnotnull</structfield> represents a not-null
+ constraint on a type. Used for domains only.
</para></entry>
</row>
<row>
- <entry>typbasetype</entry>
+ <entry><structfield>typbasetype</structfield></entry>
<entry><type>oid</type></entry>
- <entry>pg_type.oid</entry>
+ <entry><literal>pg_type.oid</literal></entry>
<entry><para>
If this is a derived type (see <structfield>typtype</structfield>),
then <structfield>typbasetype</structfield> identifies
</row>
<row>
- <entry>typtypmod</entry>
+ <entry><structfield>typtypmod</structfield></entry>
<entry><type>int4</type></entry>
<entry></entry>
<entry><para>
- Domains use <structfield>typtypmod</structfield> to record the typmod
+ Domains use <structfield>typtypmod</structfield> to record the <literal>typmod</>
to be applied to their base type (-1 if base type does not use a
- typmod). -1 if this type is not a domain.
+ <literal>typmod</>). -1 if this type is not a domain.
</para></entry>
</row>
<row>
- <entry>typndims</entry>
+ <entry><structfield>typndims</structfield></entry>
<entry><type>int4</type></entry>
<entry></entry>
<entry><para>
<structfield>typndims</structfield> is the number of array dimensions
for a domain that is an array (that is, typbasetype is an array type;
the domain's typelem will match the base type's typelem).
- Zero for non-domains and non-array domains.
+ Zero for types other than array domains.
</para></entry>
</row>
<row>
- <entry>typdefaultbin</entry>
+ <entry><structfield>typdefaultbin</structfield></entry>
<entry><type>text</type></entry>
<entry></entry>
<entry><para>
- If <structfield>typdefaultbin</> is not NULL, it is the nodeToString
- representation of a default expression for the type. Currently this is
+ If <structfield>typdefaultbin</> is not null, it is the <function>nodeToString()</function>
+ representation of a default expression for the type. This is
only used for domains.
</para></entry>
</row>
<row>
- <entry>typdefault</entry>
+ <entry><structfield>typdefault</structfield></entry>
<entry><type>text</type></entry>
<entry></entry>
<entry><para>
- <structfield>typdefault</> is NULL if the type has no associated
- default value. If <structfield>typdefaultbin</> is not NULL,
+ <structfield>typdefault</> is null if the type has no associated
+ default value. If <structfield>typdefaultbin</> is not null,
<structfield>typdefault</> must contain a human-readable version of the
default expression represented by <structfield>typdefaultbin</>. If
- <structfield>typdefaultbin</> is NULL and <structfield>typdefault</> is
+ <structfield>typdefaultbin</> is null and <structfield>typdefault</> is
not, then <structfield>typdefault</> is the external representation of
the type's default value, which may be fed to the type's input
converter to produce a constant.
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