* do instructions or hints to the planner using C-style block comments
* of the SQL.
*
- * Copyright (c) 2012, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
+ * Copyright (c) 2012-2013, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
*
*-------------------------------------------------------------------------
*/
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/rel.h"
+#include "utils/syscache.h"
#if PG_VERSION_NUM >= 90200
#include "catalog/pg_class.h"
#endif
+#include "executor/spi.h"
+#include "catalog/pg_type.h"
+/*
+ * We have our own header file "plpgsql-9.1", which is necessary to support
+ * hints for queries in PL/pgSQL blocks, in pg_hint_plan source package,
+ * because PostgreSQL 9.1 doesn't provide the header file as a part of
+ * installation. This header file is a copy of src/pl/plpgsql/src/plpgsql.h in
+ * PostgreSQL 9.1.9 source tree,
+ *
+ * On the other hand, 9.2 installation provides that header file for external
+ * modules, so we include the header in ordinary place.
+ */
+#if PG_VERSION_NUM >= 90200
+#include "plpgsql.h"
+#else
+#include "plpgsql-9.1.h"
+#endif
+
+/* partially copied from pg_stat_statements */
+#include "normalize_query.h"
+
#ifdef PG_MODULE_MAGIC
PG_MODULE_MAGIC;
#endif
unsigned char enforce_mask;
} ScanMethodHint;
+typedef struct ParentIndexInfo
+{
+ bool indisunique;
+ Oid method;
+ List *column_names;
+ char *expression_str;
+ Oid *indcollation;
+ Oid *opclass;
+ int16 *indoption;
+ char *indpred_str;
+} ParentIndexInfo;
+
/* join method hints */
typedef struct JoinMethodHint
{
Index parent_relid; /* inherit parent table relid */
Oid parent_rel_oid; /* inherit parent table relid */
ScanMethodHint *parent_hint; /* inherit parent table scan hint */
- List *parent_ind_atts; /* attnums of inherit parent table's
+ List *parent_index_infos; /* information of inherit parent table's
* index */
/* for join method hints */
RelOptInfo *pg_hint_plan_make_join_rel(PlannerInfo *root, RelOptInfo *rel1,
RelOptInfo *rel2);
+static void pg_hint_plan_plpgsql_stmt_beg(PLpgSQL_execstate *estate,
+ PLpgSQL_stmt *stmt);
+static void pg_hint_plan_plpgsql_stmt_end(PLpgSQL_execstate *estate,
+ PLpgSQL_stmt *stmt);
+
/* GUC variables */
static bool pg_hint_plan_enable_hint = true;
static bool pg_hint_plan_debug_print = false;
static int pg_hint_plan_parse_messages = INFO;
+/* Default is off, to keep backward compatibility. */
+static bool pg_hint_plan_enable_hint_table = false;
static const struct config_enum_entry parse_messages_level_options[] = {
{"debug", DEBUG2, true},
};
/*
+ * PL/pgSQL plugin for retrieving string representation of each query during
+ * function execution.
+ */
+const char *plpgsql_query_string = NULL;
+PLpgSQL_plugin plugin_funcs = {
+ NULL,
+ NULL,
+ NULL,
+ pg_hint_plan_plpgsql_stmt_beg,
+ pg_hint_plan_plpgsql_stmt_end,
+ NULL,
+ NULL,
+};
+
+/* Current nesting depth of SPI calls, used to prevent recursive calls */
+static int nested_level = 0;
+
+/*
* Module load callbacks
*/
void
_PG_init(void)
{
+ PLpgSQL_plugin **var_ptr;
+
/* Define custom GUC variables. */
DefineCustomBoolVariable("pg_hint_plan.enable_hint",
"Force planner to use plans specified in the hint comment preceding to the query.",
NULL,
NULL);
+ DefineCustomBoolVariable("pg_hint_plan.enable_hint_table",
+ "Force planner to not get hint by using table lookups.",
+ NULL,
+ &pg_hint_plan_enable_hint_table,
+ false,
+ PGC_USERSET,
+ 0,
+ NULL,
+ NULL,
+ NULL);
+
/* Install hooks. */
prev_ProcessUtility = ProcessUtility_hook;
ProcessUtility_hook = pg_hint_plan_ProcessUtility;
get_relation_info_hook = pg_hint_plan_get_relation_info;
prev_join_search = join_search_hook;
join_search_hook = pg_hint_plan_join_search;
+
+ /* setup PL/pgSQL plugin hook */
+ var_ptr = (PLpgSQL_plugin **) find_rendezvous_variable("PLpgSQL_plugin");
+ *var_ptr = &plugin_funcs;
}
/*
void
_PG_fini(void)
{
+ PLpgSQL_plugin **var_ptr;
+
/* Uninstall hooks. */
ProcessUtility_hook = prev_ProcessUtility;
planner_hook = prev_planner;
get_relation_info_hook = prev_get_relation_info;
join_search_hook = prev_join_search;
+
+ /* uninstall PL/pgSQL plugin hook */
+ var_ptr = (PLpgSQL_plugin **) find_rendezvous_variable("PLpgSQL_plugin");
+ *var_ptr = NULL;
}
/*
hstate->parent_relid = 0;
hstate->parent_rel_oid = InvalidOid;
hstate->parent_hint = NULL;
- hstate->parent_ind_atts = NIL;
+ hstate->parent_index_infos = NIL;
hstate->join_hints = NULL;
hstate->init_join_mask = 0;
hstate->join_hint_level = NULL;
hstate->all_hints[i]->delete_func(hstate->all_hints[i]);
if (hstate->all_hints)
pfree(hstate->all_hints);
- if (hstate->parent_ind_atts)
- list_free(hstate->parent_ind_atts);
+ if (hstate->parent_index_infos)
+ list_free(hstate->parent_index_infos);
}
/*
}
/*
- * Append string which repserents all hints in a given state to buf, with
+ * Append string which represents all hints in a given state to buf, with
* preceding title with them.
*/
static void
pfree(buf.data);
}
+
+/*
+ * Get hints from table by client-supplied query string and application name.
+ */
+static const char *
+get_hints_from_table(const char *client_query, const char *client_application)
+{
+ const char *search_query =
+ "SELECT hints "
+ " FROM hint_plan.hints "
+ " WHERE norm_query_string = $1 "
+ " AND ( application_name = $2 "
+ " OR application_name = '' ) "
+ " ORDER BY application_name DESC";
+ static SPIPlanPtr plan = NULL;
+ char *hints = NULL;
+ Oid argtypes[2] = { TEXTOID, TEXTOID };
+ Datum values[2];
+ bool nulls[2] = { false, false };
+ text *qry;
+ text *app;
+
+ PG_TRY();
+ {
+ ++nested_level;
+
+ SPI_connect();
+
+ if (plan == NULL)
+ {
+ SPIPlanPtr p;
+ p = SPI_prepare(search_query, 2, argtypes);
+ plan = SPI_saveplan(p);
+ SPI_freeplan(p);
+ }
+
+ qry = cstring_to_text(client_query);
+ app = cstring_to_text(client_application);
+ values[0] = PointerGetDatum(qry);
+ values[1] = PointerGetDatum(app);
+
+ SPI_execute_plan(plan, values, nulls, true, 1);
+
+ if (SPI_processed > 0)
+ {
+ char *buf;
+
+ hints = SPI_getvalue(SPI_tuptable->vals[0],
+ SPI_tuptable->tupdesc, 1);
+ /*
+ * Here we use SPI_palloc to ensure that hints string is valid even
+ * after SPI_finish call. We can't use simple palloc because it
+ * allocates memory in SPI's context and that context is deleted in
+ * SPI_finish.
+ */
+ buf = SPI_palloc(strlen(hints) + 1);
+ strcpy(buf, hints);
+ hints = buf;
+ }
+
+ SPI_finish();
+
+ --nested_level;
+ }
+ PG_CATCH();
+ {
+ --nested_level;
+ PG_RE_THROW();
+ }
+ PG_END_TRY();
+
+ return hints;
+}
+
/*
- * Do basic parsing of the query head comment.
+ * Get client-supplied query string.
*/
-static HintState *
-parse_head_comment(Query *parse)
+static const char *
+get_query_string(void)
{
const char *p;
- char *head;
- char *tail;
- int len;
- int i;
- HintState *hstate;
- /* get client-supplied query string. */
if (stmt_name)
{
PreparedStatement *entry;
entry = FetchPreparedStatement(stmt_name, true);
p = entry->plansource->query_string;
}
+ else if (plpgsql_query_string)
+ p = plpgsql_query_string;
else
p = debug_query_string;
+ return p;
+}
+
+/*
+ * Get hints from the head block comment in client-supplied query string.
+ */
+static const char *
+get_hints_from_comment(const char *p)
+{
+ const char *hint_head;
+ char *head;
+ char *tail;
+ int len;
+
if (p == NULL)
return NULL;
/* extract query head comment. */
- len = strlen(HINT_START);
- skip_space(p);
- if (strncmp(p, HINT_START, len))
+ hint_head = strstr(p, HINT_START);
+ if (hint_head == NULL)
return NULL;
+ for (;p < hint_head; p++)
+ {
+ /*
+ * Allow these characters precedes hint comment:
+ * - digits
+ * - alphabets which are in ASCII range
+ * - space, tabs and new-lines
+ * - underscores, for identifier
+ * - commas, for SELECT clause, EXPLAIN and PREPARE
+ * - parentheses, for EXPLAIN and PREPARE
+ *
+ * Note that we don't use isalpha() nor isalnum() in ctype.h here to
+ * avoid behavior which depends on locale setting.
+ */
+ if (!(*p >= '0' && *p <= '9') &&
+ !(*p >= 'A' && *p <= 'Z') &&
+ !(*p >= 'a' && *p <= 'z') &&
+ !isspace(*p) &&
+ *p != '_' &&
+ *p != ',' &&
+ *p != '(' && *p != ')')
+ return NULL;
+ }
+ len = strlen(HINT_START);
head = (char *) p;
p += len;
skip_space(p);
head[len] = '\0';
p = head;
+ return p;
+}
+
+/*
+ * Parse hints that got, create hint struct from parse tree and parse hints.
+ */
+static HintState *
+create_hintstate(Query *parse, const char *hints)
+{
+ const char *p;
+ int i;
+ HintState *hstate;
+
+ if (hints == NULL)
+ return NULL;
+
+ p = hints;
hstate = HintStateCreate();
- hstate->hint_str = head;
+ hstate->hint_str = (char *) hints;
/* parse each hint. */
parse_hints(hstate, parse, p);
/*
* If an object (or a set of objects) has multiple hints of same hint-type,
- * only the last hint is valid and others are igonred in planning.
+ * only the last hint is valid and others are ignored in planning.
* Hints except the last are marked as 'duplicated' to remember the order.
*/
for (i = 0; i < hstate->nall_hints - 1; i++)
{
Node *node;
- if (!pg_hint_plan_enable_hint)
+ /*
+ * Use standard planner if pg_hint_plan is disabled or current nesting
+ * depth is nesting depth of SPI calls.
+ */
+ if (!pg_hint_plan_enable_hint || nested_level > 0)
{
if (prev_ProcessUtility)
(*prev_ProcessUtility) (parsetree, queryString, params,
static PlannedStmt *
pg_hint_plan_planner(Query *parse, int cursorOptions, ParamListInfo boundParams)
{
+ const char *hints = NULL;
+ const char *query;
+ char *norm_query;
+ pgssJumbleState jstate;
+ int query_len;
int save_nestlevel;
PlannedStmt *result;
HintState *hstate;
/*
- * Use standard planner if pg_hint_plan is disabled. Other hook functions
- * try to change plan with current_hint if any, so set it to NULL.
+ * Use standard planner if pg_hint_plan is disabled or current nesting
+ * depth is nesting depth of SPI calls. Other hook functions try to change
+ * plan with current_hint if any, so set it to NULL.
*/
- if (!pg_hint_plan_enable_hint)
- {
- current_hint = NULL;
+ if (!pg_hint_plan_enable_hint || nested_level > 0)
+ goto standard_planner_proc;
- if (prev_planner)
- return (*prev_planner) (parse, cursorOptions, boundParams);
- else
- return standard_planner(parse, cursorOptions, boundParams);
- }
+ /* Create hint struct from client-supplied query string. */
+ query = get_query_string();
- /* Create hint struct from parse tree. */
- hstate = parse_head_comment(parse);
+ /*
+ * Create hintstate from hint specified for the query, if any.
+ *
+ * First we lookup hint in pg_hint.hints table by normalized query string,
+ * unless pg_hint_plan.enable_hint_table is OFF.
+ * This parameter provides option to avoid overhead of table lookup during
+ * planning.
+ *
+ * If no hint was found, then we try to get hint from special query comment.
+ */
+ if (pg_hint_plan_enable_hint_table)
+ {
+ /*
+ * Search hint information which is stored for the query and the
+ * application. Query string is normalized before using in condition
+ * in order to allow fuzzy matching.
+ *
+ * XXX: normalizing code is copied from pg_stat_statements.c, so be
+ * careful when supporting PostgreSQL's version up.
+ */
+ jstate.jumble = (unsigned char *) palloc(JUMBLE_SIZE);
+ jstate.jumble_len = 0;
+ jstate.clocations_buf_size = 32;
+ jstate.clocations = (pgssLocationLen *)
+ palloc(jstate.clocations_buf_size * sizeof(pgssLocationLen));
+ jstate.clocations_count = 0;
+ JumbleQuery(&jstate, parse);
+ /*
+ * generate_normalized_query() copies exact given query_len bytes, so we
+ * add 1 byte for null-termination here. As comments on
+ * generate_normalized_query says, generate_normalized_query doesn't
+ * take care of null-terminate, but additional 1 byte ensures that '\0'
+ * byte in the source buffer to be copied into norm_query.
+ */
+ query_len = strlen(query) + 1;
+ norm_query = generate_normalized_query(&jstate,
+ query,
+ &query_len,
+ GetDatabaseEncoding());
+ hints = get_hints_from_table(norm_query, application_name);
+ elog(DEBUG1,
+ "pg_hint_plan: get_hints_from_table [%s][%s]=>[%s]",
+ norm_query, application_name, hints ? hints : "(none)");
+ }
+ if (hints == NULL)
+ hints = get_hints_from_comment(query);
+ hstate = create_hintstate(parse, hints);
/*
* Use standard planner if the statement has not valid hint. Other hook
* NULL.
*/
if (!hstate)
- {
- current_hint = NULL;
-
- if (prev_planner)
- return (*prev_planner) (parse, cursorOptions, boundParams);
- else
- return standard_planner(parse, cursorOptions, boundParams);
- }
+ goto standard_planner_proc;
/*
* Push new hint struct to the hint stack to disable previous hint context.
pop_hint();
return result;
+
+standard_planner_proc:
+ current_hint = NULL;
+ if (prev_planner)
+ return (*prev_planner) (parse, cursorOptions, boundParams);
+ else
+ return standard_planner(parse, cursorOptions, boundParams);
}
/*
}
}
+ /*
+ * to make the index a candidate when definition of this index is
+ * matched with the index's definition of current_hint.
+ */
if (OidIsValid(relationObjectId) && !use_index)
{
- int i;
- char *child_attname = NULL;
- char *parent_attname = NULL;
-
- foreach(l, current_hint->parent_ind_atts)
+ foreach(l, current_hint->parent_index_infos)
{
- List *attnums = (List *)lfirst(l);
+ int i;
+ HeapTuple ht_idx;
+ ParentIndexInfo *p_info = (ParentIndexInfo *)lfirst(l);
+
+ /* check to match the parameter of unique */
+ if (p_info->indisunique != info->unique)
+ continue;
+
+ /* check to match the parameter of index's method */
+ if (p_info->method != info->relam)
+ continue;
- if ((list_length(attnums)) != info->ncolumns)
+ /* to check to match the indexkey's configuration */
+ if ((list_length(p_info->column_names)) !=
+ info->ncolumns)
continue;
+ /* check to match the indexkey's configuration */
for (i = 0; i < info->ncolumns; i++)
{
- child_attname = get_attname(relationObjectId,
- info->indexkeys[i]);
- parent_attname = get_attname(current_hint->parent_rel_oid,
- list_nth_int(attnums, i));
- /* if one's column is expression, they are different */
- if (!parent_attname || !child_attname)
+ char *c_attname = NULL;
+ char *p_attname = NULL;
+
+ p_attname =
+ list_nth(p_info->column_names, i);
+
+ /* both are expressions */
+ if (info->indexkeys[i] == 0 && !p_attname)
continue;
- if (strcmp(parent_attname, child_attname) != 0)
- {
- use_index = false;
+ /* one's column is expression, the other is not */
+ if (info->indexkeys[i] == 0 || !p_attname)
+ break;
+
+ c_attname = get_attname(relationObjectId,
+ info->indexkeys[i]);
+
+ if (strcmp(p_attname, c_attname) != 0)
+ break;
+
+ if (p_info->indcollation[i] != info->indexcollations[i])
+ break;
+
+ if (p_info->opclass[i] != info->opcintype[i])
+ break;
+
+ if (((p_info->indoption[i] & INDOPTION_DESC) != 0) !=
+ info->reverse_sort[i])
+ break;
+
+ if (((p_info->indoption[i] & INDOPTION_NULLS_FIRST) != 0) !=
+ info->nulls_first[i])
break;
- }
- use_index = true;
}
- if (use_index)
+ if (i != info->ncolumns)
+ continue;
+
+ if ((p_info->expression_str && (info->indexprs != NIL)) ||
+ (p_info->indpred_str && (info->indpred != NIL)))
{
- if (pg_hint_plan_debug_print)
+ /*
+ * Fetch the pg_index tuple by the Oid of the index
+ */
+ ht_idx = SearchSysCache1(INDEXRELID,
+ ObjectIdGetDatum(info->indexoid));
+
+ /* check to match the expression's parameter of index */
+ if (p_info->expression_str &&
+ !heap_attisnull(ht_idx, Anum_pg_index_indexprs))
{
- appendStringInfoCharMacro(&buf, ' ');
- quote_value(&buf, indexname);
+ Datum exprsDatum;
+ bool isnull;
+ Datum result;
+
+ /*
+ * to change the expression's parameter of child's
+ * index to strings
+ */
+ exprsDatum = SysCacheGetAttr(INDEXRELID, ht_idx,
+ Anum_pg_index_indexprs,
+ &isnull);
+
+ result = DirectFunctionCall2(pg_get_expr,
+ exprsDatum,
+ ObjectIdGetDatum(
+ relationObjectId));
+
+ if (strcmp(p_info->expression_str,
+ text_to_cstring(DatumGetTextP(result))) != 0)
+ {
+ /* Clean up */
+ ReleaseSysCache(ht_idx);
+
+ continue;
+ }
}
- break;
+ /* Check to match the predicate's parameter of index */
+ if (p_info->indpred_str &&
+ !heap_attisnull(ht_idx, Anum_pg_index_indpred))
+ {
+ Datum predDatum;
+ bool isnull;
+ Datum result;
+
+ /*
+ * to change the predicate's parameter of child's
+ * index to strings
+ */
+ predDatum = SysCacheGetAttr(INDEXRELID, ht_idx,
+ Anum_pg_index_indpred,
+ &isnull);
+
+ result = DirectFunctionCall2(pg_get_expr,
+ predDatum,
+ ObjectIdGetDatum(
+ relationObjectId));
+
+ if (strcmp(p_info->indpred_str,
+ text_to_cstring(DatumGetTextP(result))) != 0)
+ {
+ /* Clean up */
+ ReleaseSysCache(ht_idx);
+
+ continue;
+ }
+ }
+
+ /* Clean up */
+ ReleaseSysCache(ht_idx);
}
+ else if (p_info->expression_str || (info->indexprs != NIL))
+ continue;
+ else if (p_info->indpred_str || (info->indpred != NIL))
+ continue;
+
+ use_index = true;
+
+ /* to log the candidate of index */
+ if (pg_hint_plan_debug_print)
+ {
+ appendStringInfoCharMacro(&buf, ' ');
+ quote_value(&buf, indexname);
+ }
+
+ break;
}
}
+
if (!use_index)
rel->indexlist = list_delete_cell(rel->indexlist, cell, prev);
else
}
}
+/*
+ * Return information of index definition.
+ */
+static ParentIndexInfo *
+get_parent_index_info(Oid indexoid, Oid relid)
+{
+ ParentIndexInfo *p_info = palloc(sizeof(ParentIndexInfo));
+ Relation indexRelation;
+ Form_pg_index index;
+ char *attname;
+ int i;
+
+ indexRelation = index_open(indexoid, RowExclusiveLock);
+
+ index = indexRelation->rd_index;
+
+ p_info->indisunique = index->indisunique;
+ p_info->method = indexRelation->rd_rel->relam;
+
+ p_info->column_names = NIL;
+ p_info->indcollation = (Oid *) palloc(sizeof(Oid) * index->indnatts);
+ p_info->opclass = (Oid *) palloc(sizeof(Oid) * index->indnatts);
+ p_info->indoption = (int16 *) palloc(sizeof(Oid) * index->indnatts);
+
+ for (i = 0; i < index->indnatts; i++)
+ {
+ attname = get_attname(relid, index->indkey.values[i]);
+ p_info->column_names = lappend(p_info->column_names, attname);
+
+ p_info->indcollation[i] = indexRelation->rd_indcollation[i];
+ p_info->opclass[i] = indexRelation->rd_opcintype[i];
+ p_info->indoption[i] = indexRelation->rd_indoption[i];
+ }
+
+ /*
+ * to check to match the expression's parameter of index with child indexes
+ */
+ p_info->expression_str = NULL;
+ if(!heap_attisnull(indexRelation->rd_indextuple, Anum_pg_index_indexprs))
+ {
+ Datum exprsDatum;
+ bool isnull;
+ Datum result;
+
+ exprsDatum = SysCacheGetAttr(INDEXRELID, indexRelation->rd_indextuple,
+ Anum_pg_index_indexprs, &isnull);
+
+ result = DirectFunctionCall2(pg_get_expr,
+ exprsDatum,
+ ObjectIdGetDatum(relid));
+
+ p_info->expression_str = text_to_cstring(DatumGetTextP(result));
+ }
+
+ /*
+ * to check to match the predicate's parameter of index with child indexes
+ */
+ p_info->indpred_str = NULL;
+ if(!heap_attisnull(indexRelation->rd_indextuple, Anum_pg_index_indpred))
+ {
+ Datum predDatum;
+ bool isnull;
+ Datum result;
+
+ predDatum = SysCacheGetAttr(INDEXRELID, indexRelation->rd_indextuple,
+ Anum_pg_index_indpred, &isnull);
+
+ result = DirectFunctionCall2(pg_get_expr,
+ predDatum,
+ ObjectIdGetDatum(relid));
+
+ p_info->indpred_str = text_to_cstring(DatumGetTextP(result));
+ }
+
+ index_close(indexRelation, NoLock);
+
+ return p_info;
+}
+
static void
pg_hint_plan_get_relation_info(PlannerInfo *root, Oid relationObjectId,
bool inhparent, RelOptInfo *rel)
if (prev_get_relation_info)
(*prev_get_relation_info) (root, relationObjectId, inhparent, rel);
- /* Do nothing if we don't have valid hint in this context. */
- if (!current_hint)
+ /*
+ * Do nothing if we don't have valid hint in this context or current
+ * nesting depth is nesting depth of SPI calls.
+ */
+ if (!current_hint || nested_level > 0)
return;
if (inhparent)
foreach(l, indexoidlist)
{
- int i;
Oid indexoid = lfirst_oid(l);
char *indexname = get_rel_name(indexoid);
bool use_index = false;
- Relation indexRelation;
- Form_pg_index index;
ListCell *lc;
- List *attnums = NIL;
+ ParentIndexInfo *parent_index_info;
foreach(lc, hint->indexnames)
{
if (!use_index)
continue;
- indexRelation = index_open(indexoid, RowExclusiveLock);
-
- index = indexRelation->rd_index;
-
- for (i = 0; i < index->indnatts; i++)
- attnums = lappend_int(attnums, index->indkey.values[i]);
-
- current_hint->parent_ind_atts =
- lappend(current_hint->parent_ind_atts, attnums);
-
- index_close(indexRelation, NoLock);
+ parent_index_info = get_parent_index_info(indexoid,
+ relationObjectId);
+ current_hint->parent_index_infos =
+ lappend(current_hint->parent_index_infos, parent_index_info);
}
heap_close(relation, NoLock);
}
/*
* Use standard planner (or geqo planner) if pg_hint_plan is disabled or no
- * valid hint is supplied.
+ * valid hint is supplied or current nesting depth is nesting depth of SPI
+ * calls.
*/
- if (!current_hint)
+ if (!current_hint || nested_level > 0)
{
if (prev_join_search)
return (*prev_join_search) (root, levels_needed, initial_rels);
}
}
+/*
+ * stmt_beg callback is called when each query in PL/pgSQL function is about
+ * to be executed. At that timing, we save query string in the global variable
+ * plpgsql_query_string to use it in planner hook. It's safe to use one global
+ * variable for the purpose, because its content is only necessary until
+ * planner hook is called for the query, so recursive PL/pgSQL function calls
+ * don't harm this mechanism.
+ */
+static void
+pg_hint_plan_plpgsql_stmt_beg(PLpgSQL_execstate *estate, PLpgSQL_stmt *stmt)
+{
+ if ((enum PLpgSQL_stmt_types) stmt->cmd_type == PLPGSQL_STMT_EXECSQL)
+ {
+ PLpgSQL_expr *expr = ((PLpgSQL_stmt_execsql *) stmt)->sqlstmt;
+ plpgsql_query_string = expr->query;
+ }
+}
+
+/*
+ * stmt_end callback is called then each query in PL/pgSQL function has
+ * finished. At that timing, we clear plpgsql_query_string to tell planner
+ * hook that next call is not for a query written in PL/pgSQL block.
+ */
+static void
+pg_hint_plan_plpgsql_stmt_end(PLpgSQL_execstate *estate, PLpgSQL_stmt *stmt)
+{
+ if ((enum PLpgSQL_stmt_types) stmt->cmd_type == PLPGSQL_STMT_EXECSQL)
+ plpgsql_query_string = NULL;
+}
+
#define standard_join_search pg_hint_plan_standard_join_search
#define join_search_one_level pg_hint_plan_join_search_one_level
#define make_join_rel make_join_rel_wrapper
#define make_join_rel pg_hint_plan_make_join_rel
#define add_paths_to_joinrel add_paths_to_joinrel_wrapper
#include "make_join_rel.c"
+
+#include "pg_stat_statements.c"
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