.\" This is -*-nroff-*-
.\" XXX standard disclaimer belongs here....
-.\" $Header: /cvsroot/pgsql/src/man/Attic/pgbuiltin.3,v 1.9 1997/11/17 22:15:03 momjian Exp $
+.\" $Header: /cvsroot/pgsql/src/man/Attic/pgbuiltin.3,v 1.10 1997/11/18 23:04:27 momjian Exp $
.TH PGBUILTIN INTRO 04/01/97 PostgreSQL PostgreSQL
+.PP
.SH "DESCRIPTION"
This section describes the data types, functions and operators
available to users in Postgres as it is distributed.
+.PP
.SH "PGBUILTIN TYPES"
-This section describes
-.BR pgbuiltin
-data types.
-These Built-in types are installed in every database.
+Built-in types are installed in every database.
+.IR "psql"
+has a \ed command to show these types.
.PP
Users may add new types to Postgres using the
.IR "define type"
-command described in this manual. User-defined types are not
-described in this section.
-.SH "List of built-in types"
-.PP
-.if n .ta 5 +15 +40
-.if t .ta 0.5i +1.5i +3.0i
-.in 0
-.nf
- \fBPOSTGRES Type\fP \fBMeaning\fP
- abstime (absolute) limited-range date and time
- aclitem access control list item
- bool boolean
- box 2-dimensional rectangle
- bpchar blank-padded characters
- bytea variable length array of bytes
- char character
- char2 array of 2 characters
- char4 array of 4 characters
- char8 array of 8 characters
- char16 array of 16 characters
- cid command identifier type
- date ANSI SQL date type
- datetime general-use date and time
- filename large object filename
- int2 two-byte signed integer
- int28 array of 8 int2
- int4 four-byte signed integer
- float4 single-precision floating-point number
- float8 double-precision floating-point number
- lseg 2-dimensional line segment
- money decimal type with fixed precision
- name a multi-character type for storing system identifiers
- oid object identifier type
- oid8 array of 8 oid
- oidchar16 oid and char16 composed
- oidint2 oid and int2 composed
- oidint4 oid and int4 composed
- path open or closed line segments
- point 2-dimensional geometric point
- polygon 2-dimensional polygon (same as a closed path)
- circle 2-dimensional circle (center and radius)
- regproc registered procedure
- reltime (relative) date and time span (duration)
- smgr storage manager
- text variable length array of characters
- tid tuple identifier type
- time ANSI SQL time type
- timespan general-use time span (duration)
- timestamp limited-range ISO-format date and time
- tinterval time interval (start and stop abstime)
- varchar variable-length characters
- xid transaction identifier type
-
-.fi
-.in
+command described in this manual.
.PP
There are some data types defined by SQL/92 syntax which are mapped directly
into native Postgres types. Note that the "exact numerics"
.IR numeric
have fully implemented syntax but currently (postgres v6.2) support only a limited
range of the values allowed by SQL/92.
-
+.PP
.SH "List of SQL/92 types"
.PP
-.if n .ta 5 +15 +25 +40
+.if n .ta 2 +15 +25 +40
.if t .ta 0.5i +1.5i +3.0i
.in 0
.nf
.in
.PP
There are some constants and functions defined in SQL/92.
+.PP
.SH "List of SQL/92 constants"
.PP
-.if n .ta 5 +20 +40
+.if n .ta 2 +20 +40
.if t .ta 0.5i +1.5i +3.0i +4.0i
.in 0
.nf
Many of the built-in types have obvious external formats. However, several
types are either unique to Postgres, such as open and closed paths, or have
several possibilities for formats, such as date and time types.
-
+.PP
.SH "Syntax of date and time types"
Most date and time types share code for data input. For those types (
.IR datetime ,
implementation of datetime becoming timestamp, timespan becoming interval,
and (possibly) abstime
and reltime being deprecated in favor of timestamp and interval.
-
+.PP
.SH "DATETIME"
General-use date and time is input using a wide range of
styles, including ISO-compatible, SQL-compatible, traditional
time values. `now' means the current time, and differs from
`current' in that the current time is immediately substituted
for it. `epoch' means Jan 1 00:00:00 1970 GMT.
-
+.PP
.SH "TIMESPAN"
General-use time span is input using a wide range of
syntaxes, including ISO-compatible, SQL-compatible, traditional
or abbreviations or plurals of these units.
Direction is `ago'.
.fi
+.PP
.SH "ABSOLUTE TIME"
Absolute time (abstime) is a limited-range (+/- 68 years) and limited-precision (1 sec)
date data type.
.IR "datetime"
are also allowed for
.IR "absolute time".
-
+.PP
.SH "RELATIVE TIME"
Relative time (reltime) is a limited-range (+/- 68 years) and limited-precision (1 sec)
time span data type.
Valid relative times are less than or equal to 68 years.)
In addition, the special relative time \*(lqUndefined RelTime\*(rq is
provided.
-
+.PP
.SH "TIMESTAMP"
This is currently a limited-range absolute time which closely resembles the
.IR abstime
.PP
timestamp is specified using the same syntax as for datetime.
-
+.PP
.SH "TIME RANGES"
Time ranges are specified as:
.PP
.IR abstime
is a time in the absolute time format. Special abstime values such as
\*(lqcurrent\*(rq, \*(lqinfinity\*(rq and \*(lq-infinity\*(rq can be used.
-
+.PP
.SH "Syntax of geometric types"
.SH "POINT"
Points are specified using the following syntax:
the lower left corner first and the upper right corner last.
Other corners of the box can be entered, but the lower
left and upper right corners are determined from the input and stored.
+.PP
.SH "PATH"
Paths are represented by sets of points. Paths can be "open", where
the first and last points in the set are not connected, and "closed",
an integer count of the number of points, then the list of points followed by a
closing parenthesis. The built-in function upgradepath() is supplied to convert
paths dumped and reloaded from pre-v6.1 databases.
-
+.PP
.SH "POLYGON"
Polygons are represented by sets of points. Polygons should probably be
considered
of x-axis coordinates, the list of y-axis coordinates, followed by a closing parenthesis.
The built-in function upgradepoly() is supplied to convert
polygons dumped and reloaded from pre-v6.1 databases.
-
+.PP
.SH "CIRCLE"
Circles are represented by a center point and a radius.
.PP
.fi
.PP
Circles are output using the first syntax.
-
+.PP
.SH "Built-in operators and functions"
.SH OPERATORS
Postgres provides a large number of built-in operators on system types.
\*(lqpg_operator\*(rq. Every entry in \*(lqpg_operator\*(rq includes
the object ID of the procedure that implements the operator.
.PP
-Users may invoke operators using the operator name, as in
+Users may invoke operators using the operator name, as in:
+.PP
+.in 1i
.nf
select * from emp where salary < 40000;
.fi
+.in
+.PP
Alternatively, users may call the functions that implement the
operators directly. In this case, the query above would be expressed
-as
+as:
+.PP
+.in 1i
.nf
select * from emp where int4lt(salary, 40000);
.fi
-The rest of this section provides a list of the built-in operators and
-the functions that implement them. Binary operators are listed first,
-followed by unary operators.
-
-.nf
-Operators:
-
-general
- <\(eq less or equal
- <> inequality
- < less than
- <\(eq greater or equal
- >\(eq greater or equal
- > greater than
- \(eq equality
- ~ A matches regular expression B, case-sensitive
- !~ A does not match regular expression B, case-sensitive
- ~* A matches regular expression B, case-insensitive.
- !~* A does not match regular expression B, case-insensitive
- ~~ A matches LIKE expression B, case-sensitive
- !~~ A does not match LIKE expression B, case-sensitive
-
- + addition
- \(mi subtraction
- * multiplication
- / division
- % modulus
- @ absolute value
-
-geometric
- @ A contained by (inside or on) B
- ~ A contains (around or on) B
- @@ center of object
- <-> distance between A and B
- && objects overlap
- &< A overlaps B, but does not extend to right of B
- &> A overlaps B, but does not extend to left of B
- << A is left of B
- >> A is right of B
- >^ A is above B
- <^ A is below B
-
-float8
- ^ exponentiation
- % truncate to integer
- |/ square root
- ||/ cube root
- : exponential function
- ; natural logarithm (in psql, protect with parentheses)
-
-point
- << A is left of B
- >> A is right of B
- >^ A is above B
- <^ A is below B
- ~\(eq A same as B (equality)
- @ point inside (or on) path, box, circle, polygon
-
-box
- && boxes overlap
- &< box A overlaps box B, but does not extend to right of box B
- &> box A overlaps box B, but does not extend to left of box B
- << A is left of B
- >> A is right of B
- >^ A is above B
- <^ A is below B
- \(eq area equal
- < area less than
- <\(eq area less or equal
- >\(eq area greater or equal
- > area greater than
- ~\(eq A same as B (equality)
- @ A is contained in B
- ~ A contains B
- @@ center of box
-
-polygon
- && polygons overlap
- &< A overlaps B but does not extend to right of B
- &> A overlaps B but does not extend to left of B
- << A is left of B
- >> A is right of B
- ~\(eq A same as B (equality)
- @ A is contained by B
- ~ A contains B
-
-circle
- && circles overlap
- &< A overlaps B but does not extend to right of B
- &> A overlaps B but does not extend to left of B
- << A is left of B
- >> A is right of B
- >^ A is above B
- <^ A is below B
- ~\(eq A same as B (equality)
- @ A is contained by B
- ~ A contains B
-
-tinterval
- #<\(eq interval length less or equal reltime
- #<> interval length not equal to reltime.
- #< interval length less than reltime
- #\(eq interval length equal to reltime
- #>\(eq interval length greater or equal reltime
- #> interval length greater than reltime
- && intervals overlap
- << A contains B
- \(eq equality
- <> interval bounded by two abstimes
- <?> abstime in tinterval
- | start of interval
- <#> convert to interval
-.fi
-
+.in
+.PP
+.IR "psql"
+has a \ed command to show these operators.
+.PP
.SH "FUNCTIONS"
Many data types have functions available for conversion to other related types.
In addition, there are some type-specific functions. Functions which are also
trim characters from text
.fi
-
-.SH "PSQL HELP"
-.IR "psq"
+.PP
+.SH "ADDITIONAL INFORMATION"
+.IR "psql"
has a variety of \ed commands for showing system information.
Consult those
.IR "psql"
commands for more listings.
-
-.in
+.PP
.SH "SEE ALSO"
.IR set (l),
.IR show (l),
.IR psql (1).
For examples on specifying literals of built-in types, see
.IR SQL (l).
-.SH BUGS
.PP
+.SH BUGS
Although most of the input and output functions corresponding to the
base types (e.g., integers and floating point numbers) do some
error-checking, some are not particularly rigorous about it. More
OSDN Git Service
