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pg_dbms_stats.c
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/*
* pg_dbms_stats.c
*
* Copyright (c) 2009-2018, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
* Portions Copyright (c) 1996-2013, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*/
#include "postgres.h"
#include "access/sysattr.h"
#include "access/transam.h"
#include "catalog/pg_index.h"
#include "catalog/pg_statistic.h"
#include "catalog/pg_type.h"
#include "catalog/namespace.h"
#include "catalog/pg_authid.h"
#include "commands/trigger.h"
#include "executor/spi.h"
#include "funcapi.h"
#include "optimizer/plancat.h"
#include "optimizer/planner.h"
#include "parser/parse_oper.h"
#include "parser/parsetree.h"
#include "storage/bufmgr.h"
#include "utils/acl.h"
#include "utils/builtins.h"
#include "utils/elog.h"
#include "utils/fmgroids.h"
#include "utils/guc.h"
#include "utils/inval.h"
#include "utils/lsyscache.h"
#include "utils/selfuncs.h"
#include "utils/syscache.h"
#include "miscadmin.h"
#include "utils/rel.h"
#if PG_VERSION_NUM >= 90300
#include "access/htup_details.h"
#include "utils/catcache.h"
#endif
#if PG_VERSION_NUM >= 100000
#include <math.h>
#endif
#include "pg_dbms_stats.h"
PG_MODULE_MAGIC;
/* Error levels used by pg_dbms_stats */
#define ELEVEL_DEBUG DEBUG3 /* log level for debug information */
#define ELEVEL_BADSTATS LOG /* log level for invalid statistics */
#define MAX_REL_CACHE 50 /* expected max # of rel stats entries */
/* acl_ok must be set after the fix for CVE-2017-7484 */
#if PG_VERSION_NUM >= 100000 || \
(PG_VERSION_NUM >= 90603 && PG_VERSION_NUM < 100000) || \
(PG_VERSION_NUM >= 90507 && PG_VERSION_NUM < 90600) || \
(PG_VERSION_NUM >= 90412 && PG_VERSION_NUM < 90500) || \
(PG_VERSION_NUM >= 90317 && PG_VERSION_NUM < 90400) || \
(PG_VERSION_NUM >= 90221 && PG_VERSION_NUM < 90300)
#define PGDS_HAVE_ACL_OK
/*
* acl_ok of the returning VariableStatData must be set if set_acl_okk is
* true. The code is compiled only if the compile target PG version is match
* the above conditions. Conversely, acl_ok is added to the end of
* VariableStatData so we can safely omit setting it when the PG version
* pg_dbms_stats is loaded onto is out of the conditions.
*/
static bool set_acl_ok = false;
#endif
/* FormData_pg_attribute is modifed at PG11 */
#if PG_VERSION_NUM >= 110000
#define get_attrs(pgatt_attrs) (&(pgatt_attrs))
#else
#define get_attrs(pgatt_attrs) (pgatt_attrs)
#endif
/*
* get_attrs and heap_attisnull are modifed as of PG11. They behave in the same
* way beyond the modification as long as nullok == true and desc == NULL
* respectively.
*/
#if PG_VERSION_NUM < 110000
#define get_attname(rid, attnum, nullok) \
(AssertMacro((nullok) == true), get_attname((rid), (attnum)))
#define heap_attisnull(tup, attnum, desc) \
(AssertMacro((desc) == NULL), heap_attisnull((tup), (attnum)))
#endif
/* Relation statistics cache entry */
typedef struct StatsRelationEntry
{
Oid relid; /* hash key must be at the head */
bool valid; /* T if the entry has valid stats */
bool invalidated; /* T if this relation has been
* invalidated */
BlockNumber relpages; /* # of pages as of last ANALYZE */
double reltuples; /* # of tuples as of last ANALYZE */
BlockNumber relallvisible; /* # of all-visible pages as of last
* ANALYZE */
BlockNumber curpages; /* # of pages as of lock/restore */
List *col_stats; /* list of StatsColumnEntry, each element
of which is pg_statistic record of this
relation. */
} StatsRelationEntry;
/*
* Column statistics cache entry. This is for list item for
* StatsRelationEntry.col_stats.
*/
typedef struct StatsColumnEntry
{
bool negative;
int32 attnum;
bool inh;
HeapTuple tuple;
} StatsColumnEntry;
/* Saved hook functions */
get_relation_info_hook_type prev_get_relation_info = NULL;
get_attavgwidth_hook_type prev_get_attavgwidth = NULL;
get_relation_stats_hook_type prev_get_relation_stats = NULL;
get_index_stats_hook_type prev_get_index_stats = NULL;
planner_hook_type prev_planner_hook = NULL;
/* namings */
#define NSPNAME "dbms_stats"
#define RELSTAT_TBLNAME "relation_stats_locked"
#define COLSTAT_TBLNAME "column_stats_locked"
/* rows_query(oid) RETURNS int4, float4, int4 */
static const char *rows_query =
"SELECT relpages, reltuples, curpages, relallvisible"
" FROM " NSPNAME "." RELSTAT_TBLNAME
" WHERE relid = $1";
static SPIPlanPtr rows_plan = NULL;
/* tuple_query(oid, int2, bool) RETURNS pg_statistic */
static const char *tuple_query =
"SELECT * "
" FROM " NSPNAME "." COLSTAT_TBLNAME
" WHERE starelid = $1 "
" AND staattnum = $2 "
" AND stainherit = $3";
static SPIPlanPtr tuple_plan = NULL;
/* GUC variables */
static bool pg_dbms_stats_use_locked_stats = true;
/* Current nesting depth of SPI calls, used to prevent recursive calls */
static int nested_level = 0;
/*
* The relation_stats_effective statistic cache is stored in hash table.
* rel_invalidated is set true if the hash has invalidated entries.
*/
static HTAB *rel_stats;
static bool rel_invalidated = false;
/*
* The owner of pg_dbms_stats statistic tables.
*/
static Oid stats_table_owner = InvalidOid;
static char *stats_table_owner_name = "";
#define get_pg_statistic(tuple) ((Form_pg_statistic) GETSTRUCT(tuple))
PG_FUNCTION_INFO_V1(dbms_stats_merge);
PG_FUNCTION_INFO_V1(dbms_stats_invalidate_relation_cache);
PG_FUNCTION_INFO_V1(dbms_stats_invalidate_column_cache);
PG_FUNCTION_INFO_V1(dbms_stats_is_system_schema);
PG_FUNCTION_INFO_V1(dbms_stats_is_system_catalog);
PG_FUNCTION_INFO_V1(dbms_stats_anyary_anyary);
PG_FUNCTION_INFO_V1(dbms_stats_type_is_analyzable);
PG_FUNCTION_INFO_V1(dbms_stats_anyarray_basetype);
extern Datum dbms_stats_merge(PG_FUNCTION_ARGS);
extern Datum dbms_stats_invalidate_relation_cache(PG_FUNCTION_ARGS);
extern Datum dbms_stats_invalidate_column_cache(PG_FUNCTION_ARGS);
extern Datum dbms_stats_is_system_schema(PG_FUNCTION_ARGS);
extern Datum dbms_stats_is_system_catalog(PG_FUNCTION_ARGS);
extern Datum dbms_stats_anyary_anyary(PG_FUNCTION_ARGS);
extern Datum dbms_stats_type_is_analyzable(PG_FUNCTION_ARGS);
extern Datum dbms_stats_anyarray_basetype(PG_FUNCTION_ARGS);
static HeapTuple dbms_stats_merge_internal(HeapTuple lhs, HeapTuple rhs,
TupleDesc tupledesc);
static void dbms_stats_check_tg_event(FunctionCallInfo fcinfo,
TriggerData *trigdata, HeapTuple *invtup, HeapTuple *rettup);
static void dbms_stats_invalidate_cache_internal(Oid relid, bool sta_col);
/* Module callbacks */
void _PG_init(void);
void _PG_fini(void);
/* hook functions */
static void dbms_stats_get_relation_info(PlannerInfo *root, Oid relid,
bool inhparent, RelOptInfo *rel);
static int32 dbms_stats_get_attavgwidth(Oid relid, AttrNumber attnum);
static bool dbms_stats_get_relation_stats(PlannerInfo *root, RangeTblEntry *rte,
AttrNumber attnum, VariableStatData *vardata);
static bool dbms_stats_get_index_stats(PlannerInfo *root, Oid indexOid,
AttrNumber indexattnum, VariableStatData *vardata);
static PlannedStmt *dbms_stats_planner(Query *parse, int cursorOptions,
ParamListInfo boundParams);
/* internal functions */
static void get_merged_relation_stats(Oid relid, BlockNumber *pages,
double *tuples, double *allvisfrac, bool estimate);
static int32 get_merged_avgwidth(Oid relid, AttrNumber attnum);
static HeapTuple get_merged_column_stats(Oid relid, AttrNumber attnum,
bool inh);
static HeapTuple column_cache_search(Oid relid, AttrNumber attnum,
bool inh, bool*negative);
static HeapTuple column_cache_enter(Oid relid, int32 attnum, bool inh,
HeapTuple tuple);
static bool execute_plan(SPIPlanPtr *plan, const char *query, Oid relid,
const AttrNumber *attnum, bool inh);
static void statscache_rel_callback(Datum arg, Oid relid);
static void cleanup_invalidated_cache(void);
static void init_rel_stats(void);
static void init_rel_stats_entry(StatsRelationEntry *entry, Oid relid);
/* copied from PG core source tree */
static void dbms_stats_estimate_rel_size(Relation rel, int32 *attr_widths,
BlockNumber *pages, double *tuples, double *allvisfrac,
BlockNumber curpages);
static int32 dbms_stats_get_rel_data_width(Relation rel, int32 *attr_widths);
/* Unit test suit functions */
#ifdef UNIT_TEST
extern void test_import(int *passed, int *total);
extern void test_dump(int *passed, int *total);
extern void test_pg_dbms_stats(int *passed, int *total);
#endif
/*
* Module load callback
*/
void
_PG_init(void)
{
/* Execute unit test cases */
#ifdef UNIT_TEST
{
int passed = 0;
int total = 0;
test_import(&passed, &total);
test_dump(&passed, &total);
test_pg_dbms_stats(&passed, &total);
elog(WARNING, "TOTAL %d/%d passed", passed, total);
}
#endif
#ifdef PGDS_HAVE_ACL_OK
{
/*
* Check the PG version this module loaded onto. This aid is required
* for binary backward compatibility within a major PG version.
*/
int major_version = PG_VERSION_NUM / 100;
int minor_version = PG_VERSION_NUM % 100;
if (major_version >= 1000 ||
(major_version == 906 && minor_version >= 3) ||
(major_version == 905 && minor_version >= 7) ||
(major_version == 904 && minor_version >= 12) ||
(major_version == 903 && minor_version >= 17) ||
(major_version == 902 && minor_version >= 21))
set_acl_ok = true;
}
#endif
/* Define custom GUC variables. */
DefineCustomBoolVariable("pg_dbms_stats.use_locked_stats",
"Enable user defined statistics.",
NULL,
&pg_dbms_stats_use_locked_stats,
true,
PGC_USERSET,
0,
NULL,
NULL,
NULL);
EmitWarningsOnPlaceholders("pg_dbms_stats");
/* Back up old hooks, and install ours. */
prev_get_relation_info = get_relation_info_hook;
get_relation_info_hook = dbms_stats_get_relation_info;
prev_get_attavgwidth = get_attavgwidth_hook;
get_attavgwidth_hook = dbms_stats_get_attavgwidth;
prev_get_relation_stats = get_relation_stats_hook;
get_relation_stats_hook = dbms_stats_get_relation_stats;
prev_get_index_stats = get_index_stats_hook;
get_index_stats_hook = dbms_stats_get_index_stats;
prev_planner_hook = planner_hook;
planner_hook = dbms_stats_planner;
/* Initialize hash table for statistics caching. */
init_rel_stats();
/* Also set up a callback for relcache SI invalidations */
CacheRegisterRelcacheCallback(statscache_rel_callback, (Datum) 0);
}
/*
* Module unload callback
*/
void
_PG_fini(void)
{
/* Restore old hooks. */
get_relation_info_hook = prev_get_relation_info;
get_attavgwidth_hook = prev_get_attavgwidth;
get_relation_stats_hook = prev_get_relation_stats;
get_index_stats_hook = prev_get_index_stats;
planner_hook = prev_planner_hook;
/* A function to unregister callback for relcache is NOT provided. */
}
/*
* Function to convert from any array from dbms_stats.anyarray.
*/
Datum
dbms_stats_anyary_anyary(PG_FUNCTION_ARGS)
{
ArrayType *arr = PG_GETARG_ARRAYTYPE_P(0);
if (ARR_NDIM(arr) != 1)
elog(ERROR, "array must be one-dimentional.");
PG_RETURN_ARRAYTYPE_P(arr);
}
/*
* Function to check if the type can have statistics.
*/
Datum
dbms_stats_type_is_analyzable(PG_FUNCTION_ARGS)
{
Oid typid = PG_GETARG_OID(0);
Oid eqopr;
if (!OidIsValid(typid))
PG_RETURN_BOOL(false);
get_sort_group_operators(typid, false, false, false,
NULL, &eqopr, NULL,
NULL);
PG_RETURN_BOOL(OidIsValid(eqopr));
}
/*
* Function to get base type of the value of the type dbms_stats.anyarray.
*/
Datum
dbms_stats_anyarray_basetype(PG_FUNCTION_ARGS)
{
ArrayType *arr = PG_GETARG_ARRAYTYPE_P(0);
Oid elemtype = arr->elemtype;
HeapTuple tp;
Form_pg_type typtup;
Name result;
if (!OidIsValid(elemtype))
elog(ERROR, "invalid base type oid: %u", elemtype);
tp = SearchSysCache1(TYPEOID, ObjectIdGetDatum(elemtype));
if (!HeapTupleIsValid(tp)) /* I trust you. */
elog(ERROR, "invalid base type oid: %u", elemtype);
typtup = (Form_pg_type) GETSTRUCT(tp);
result = (Name) palloc0(NAMEDATALEN);
StrNCpy(NameStr(*result), NameStr(typtup->typname), NAMEDATALEN);
ReleaseSysCache(tp);
PG_RETURN_NAME(result);
}
/*
* Find and store the owner of the dummy statistics table.
*
* We will access statistics tables using this owner
*/
static Oid
get_stats_table_owner(void)
{
HeapTuple tp;
if (!OidIsValid(stats_table_owner))
{
tp = SearchSysCache2(RELNAMENSP,
PointerGetDatum(RELSTAT_TBLNAME),
ObjectIdGetDatum(get_namespace_oid(NSPNAME, false)));
if (!HeapTupleIsValid(tp))
elog(ERROR, "table \"%s.%s\" not found in pg_class",
NSPNAME, RELSTAT_TBLNAME);
stats_table_owner = ((Form_pg_class) GETSTRUCT(tp))->relowner;
if (!OidIsValid(stats_table_owner))
elog(ERROR, "owner uid of table \"%s.%s\" is invalid",
NSPNAME, RELSTAT_TBLNAME);
ReleaseSysCache(tp);
tp = SearchSysCache1(AUTHOID, ObjectIdGetDatum(stats_table_owner));
if (!HeapTupleIsValid(tp))
{
elog(ERROR,
"role id %u for the owner of the relation \"%s.%s\"is invalid",
stats_table_owner, NSPNAME, RELSTAT_TBLNAME);
}
/* This will be done once for the session, so not pstrdup. */
stats_table_owner_name =
strdup(NameStr(((Form_pg_authid) GETSTRUCT(tp))->rolname));
ReleaseSysCache(tp);
}
return stats_table_owner;
}
/*
* Store heap tuple header into given heap tuple.
*/
static void
AssignHeapTuple(HeapTuple htup, HeapTupleHeader header)
{
htup->t_len = HeapTupleHeaderGetDatumLength(header);
ItemPointerSetInvalid(&htup->t_self);
htup->t_tableOid = InvalidOid;
htup->t_data = header;
}
/*
* dbms_stats_merge
* called by sql function 'dbms_stats.merge', and return the execution result
* of the function 'dbms_stats_merge_internal'.
*/
Datum
dbms_stats_merge(PG_FUNCTION_ARGS)
{
HeapTupleData lhs;
HeapTupleData rhs;
TupleDesc tupdesc;
HeapTuple ret = NULL;
/* assign HeapTuple of the left statistics data unless null. */
if (PG_ARGISNULL(0))
lhs.t_data = NULL;
else
AssignHeapTuple(&lhs, PG_GETARG_HEAPTUPLEHEADER(0));
/* assign HeapTuple of the right statistics data unless null. */
if (PG_ARGISNULL(1))
rhs.t_data = NULL;
else
AssignHeapTuple(&rhs, PG_GETARG_HEAPTUPLEHEADER(1));
/* fast path for one-side is null */
if (lhs.t_data == NULL && rhs.t_data == NULL)
PG_RETURN_NULL();
/* build a tuple descriptor for our result type */
if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
elog(ERROR, "return type must be a row type");
/* merge two statistics tuples into one, and return it */
ret = dbms_stats_merge_internal(&lhs, &rhs, tupdesc);
if (ret)
PG_RETURN_DATUM(HeapTupleGetDatum(ret));
else
PG_RETURN_NULL();
}
/*
* dbms_stats_merge_internal
* merge the dummy statistic (lhs) and the true statistic (rhs), on the basis
* of given TupleDesc.
*
* this function doesn't become an error level of ERROR to meet that the
* result of the SQL is not affected by the query plan.
*/
static HeapTuple
dbms_stats_merge_internal(HeapTuple lhs, HeapTuple rhs, TupleDesc tupdesc)
{
Datum values[Natts_pg_statistic];
bool nulls[Natts_pg_statistic];
int i;
Oid atttype = InvalidOid;
Oid relid;
AttrNumber attnum;
/* fast path for both-sides are null */
if ((lhs == NULL || lhs->t_data == NULL) &&
(rhs == NULL || rhs->t_data == NULL))
return NULL;
/* fast path for one-side is null */
if (lhs == NULL || lhs->t_data == NULL)
{
/* use right tuple */
heap_deform_tuple(rhs, tupdesc, values, nulls);
for (i = 0; i < Anum_pg_statistic_staop1 + STATISTIC_NUM_SLOTS - 1; i++)
if (nulls[i])
return NULL; /* check null constraints */
}
else if (rhs == NULL || rhs->t_data == NULL)
{
/* use left tuple */
heap_deform_tuple(lhs, tupdesc, values, nulls);
for (i = 0; i < Anum_pg_statistic_staop1 + STATISTIC_NUM_SLOTS - 1; i++)
if (nulls[i])
return NULL; /* check null constraints */
}
else
{
/*
* If the column value of the dummy statistic is not NULL, in the
* statistics except the slot, use it. Otherwise we use the column
* value of the true statistic.
*/
heap_deform_tuple(lhs, tupdesc, values, nulls);
for (i = 0; i < Anum_pg_statistic_stakind1 - 1; i++)
{
if (nulls[i])
{
values[i] = fastgetattr(rhs, i + 1, tupdesc, &nulls[i]);
if (nulls[i])
{
ereport(ELEVEL_BADSTATS,
(errmsg("pg_dbms_stats: bad statistics"),
errdetail("column \"%s\" should not be null",
get_attname(StatisticRelationId,
get_attrs(tupdesc->attrs[i])->attnum,
true))));
return NULL; /* should not be null */
}
}
}
/*
* If the column value of the dummy statistic is not all NULL, in the
* statistics the slot, use it. Otherwise we use the column
* value of the true statistic.
*/
for (; i < Anum_pg_statistic_staop1 + STATISTIC_NUM_SLOTS - 1; i++)
{
if (nulls[i])
{
for (i = Anum_pg_statistic_stakind1 - 1;
i < Anum_pg_statistic_stavalues1 + STATISTIC_NUM_SLOTS - 1;
i++)
{
values[i] = fastgetattr(rhs, i + 1, tupdesc, &nulls[i]);
if (i < Anum_pg_statistic_staop1 + STATISTIC_NUM_SLOTS - 1 &&
nulls[i])
{
ereport(ELEVEL_BADSTATS,
(errmsg("pg_dbms_stats: bad statistics"),
errdetail("column \"%s\" should not be null",
get_attname(StatisticRelationId,
get_attrs(tupdesc->attrs[i])->attnum,
true))));
return NULL; /* should not be null */
}
}
break;
}
}
}
/*
* Verify types to work around for ALTER COLUMN TYPE.
*
* Note: We don't need to retrieve atttype when the attribute doesn't have
* neither Most-Common-Value nor Histogram, but we retrieve it always
* because it's not usual.
*/
relid = DatumGetObjectId(values[0]);
attnum = DatumGetInt16(values[1]);
atttype = get_atttype(relid, attnum);
if (atttype == InvalidOid)
{
ereport(WARNING,
(errmsg("pg_dbms_stats: no-longer-existent column"),
errdetail("relid \"%d\" or its column whose attnum is \"%d\" might be deleted",
relid, attnum),
errhint("dbms_stats.clean_up_stats() would fix this.")));
return NULL;
}
for (i = 0; i < STATISTIC_NUM_SLOTS; i++)
{
if ((i + 1 == STATISTIC_KIND_MCV ||
i + 1 == STATISTIC_KIND_HISTOGRAM) &&
!nulls[Anum_pg_statistic_stavalues1 + i - 1])
{
ArrayType *arr;
arr = DatumGetArrayTypeP(
values[Anum_pg_statistic_stavalues1 + i - 1]);
if (arr == NULL || arr->elemtype != atttype)
{
const char *attname = get_attname(relid, attnum, true);
/*
* relid and attnum must be valid here because valid atttype
* has been gotten already.
*/
Assert(attname);
ereport(ELEVEL_BADSTATS,
(errmsg("pg_dbms_stats: bad column type"),
errdetail("type of column \"%s\" has been changed",
attname),
errhint("need to execute dbms_stats.unlock('%s', '%s')",
get_rel_name(relid), attname)));
return NULL;
}
}
}
return heap_form_tuple(tupdesc, values, nulls);
}
/*
* dbms_stats_invalidate_relation_cache
* Register invalidation of the specified relation's relcache.
*
* CREATE TRIGGER dbms_stats.relation_stats_locked FOR INSERT, UPDATE, DELETE FOR EACH
* ROWS EXECUTE ...
*/
Datum
dbms_stats_invalidate_relation_cache(PG_FUNCTION_ARGS)
{
TriggerData *trigdata = (TriggerData *) fcinfo->context;
HeapTuple invtup; /* tuple to be invalidated */
HeapTuple rettup; /* tuple to be returned */
Datum value;
bool isnull;
/* make sure it's called as a before/after trigger */
dbms_stats_check_tg_event(fcinfo, trigdata, &invtup, &rettup);
/*
* assume that position of dbms_stats.relation_stats_locked.relid is head value of
* tuple.
*/
value = fastgetattr(invtup, 1, trigdata->tg_relation->rd_att, &isnull);
/*
* invalidate prepared statements and force re-planning with pg_dbms_stats.
*/
dbms_stats_invalidate_cache_internal((Oid)value, false);
PG_RETURN_POINTER(rettup);
}
/*
* dbms_stats_invalidate_column_cache
* Register invalidation of the specified relation's relcache.
*
* CREATE TRIGGER dbms_stats.column_stats_locked FOR INSERT, UPDATE, DELETE FOR EACH
* ROWS EXECUTE ...
*/
Datum
dbms_stats_invalidate_column_cache(PG_FUNCTION_ARGS)
{
TriggerData *trigdata = (TriggerData *) fcinfo->context;
Form_pg_statistic form;
HeapTuple invtup; /* tuple to be invalidated */
HeapTuple rettup; /* tuple to be returned */
/* make sure it's called as a before/after trigger */
dbms_stats_check_tg_event(fcinfo, trigdata, &invtup, &rettup);
/*
* assume that both pg_statistic and dbms_stats.column_stats_locked have the same
* definition.
*/
form = get_pg_statistic(invtup);
/*
* invalidate prepared statements and force re-planning with pg_dbms_stats.
*/
dbms_stats_invalidate_cache_internal(form->starelid, true);
PG_RETURN_POINTER(rettup);
}
static void
dbms_stats_check_tg_event(FunctionCallInfo fcinfo,
TriggerData *trigdata,
HeapTuple *invtup,
HeapTuple *rettup)
{
/* make sure it's called as a before/after trigger */
if (!CALLED_AS_TRIGGER(fcinfo) ||
!TRIGGER_FIRED_BEFORE(trigdata->tg_event) ||
!TRIGGER_FIRED_FOR_ROW(trigdata->tg_event))
elog(ERROR, "pg_dbms_stats: invalid trigger call");
if (TRIGGER_FIRED_BY_INSERT(trigdata->tg_event))
{
/* INSERT */
*rettup = *invtup = trigdata->tg_trigtuple;
}
else if (TRIGGER_FIRED_BY_DELETE(trigdata->tg_event))
{
/* DELETE */
*rettup = *invtup = trigdata->tg_trigtuple;
}
else
{
/* UPDATE */
*invtup = trigdata->tg_trigtuple;
*rettup = trigdata->tg_newtuple;
}
}
static void
dbms_stats_invalidate_cache_internal(Oid relid, bool sta_col)
{
Relation rel;
/*
* invalidate prepared statements and force re-planning with pg_dbms_stats.
*/
rel = try_relation_open(relid, NoLock);
if (rel != NULL)
{
if (sta_col &&
rel->rd_rel->relkind == RELKIND_INDEX &&
(rel->rd_indextuple == NULL ||
heap_attisnull(rel->rd_indextuple, Anum_pg_index_indexprs, NULL)))
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is an index except an index expression",
RelationGetRelationName(rel))));
if (rel->rd_rel->relkind == RELKIND_COMPOSITE_TYPE)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is a composite type",
RelationGetRelationName(rel))));
/*
* We need to invalidate relcache of underlying table too, because
* CachedPlan mechanism decides to do re-planning when any relcache of
* used tables was invalid at EXECUTE.
*/
if (rel->rd_rel->relkind == RELKIND_INDEX &&
rel->rd_index && OidIsValid(rel->rd_index->indrelid))
CacheInvalidateRelcacheByRelid(rel->rd_index->indrelid);
CacheInvalidateRelcache(rel);
relation_close(rel, NoLock);
}
}
/*
* dbms_stats_is_system_schema
* called by sql function 'dbms_stats.is_system_schema', and return the
* result of the function 'dbms_stats_is_system_internal'.
*/
Datum
dbms_stats_is_system_schema(PG_FUNCTION_ARGS)
{
text *arg0;
char *schema_name;
bool result;
arg0 = PG_GETARG_TEXT_PP(0);
schema_name = text_to_cstring(arg0);
result = dbms_stats_is_system_schema_internal(schema_name);
PG_FREE_IF_COPY(arg0, 0);
PG_RETURN_BOOL(result);
}
/*
* dbms_stats_is_system_schema_internal
* return whether the given schema contains any system catalog. Here we
* treat dbms_stats objects as system catalogs to avoid infinite loop.
*/
bool
dbms_stats_is_system_schema_internal(char *schema_name)
{
Assert(schema_name != NULL);
/* if the schema is system_schema, return true */
if (strcmp(schema_name, "pg_catalog") == 0 ||
strcmp(schema_name, "pg_toast") == 0 ||
strcmp(schema_name, "information_schema") == 0 ||
strcmp(schema_name, NSPNAME) == 0)
return true;
return false;
}
/*
* dbms_stats_is_system_catalog
* called by sql function 'dbms_stats.is_system_catalog', and return the
* result of the function 'dbms_stats_is_system_catalog_internal'.
*/
Datum
dbms_stats_is_system_catalog(PG_FUNCTION_ARGS)
{
Oid relid;
bool result;
if (PG_ARGISNULL(0))
PG_RETURN_BOOL(true);
relid = PG_GETARG_OID(0);
result = dbms_stats_is_system_catalog_internal(relid);
PG_RETURN_BOOL(result);
}
/*
* dbms_stats_is_system_catalog_internal
* Check whether the given relation is one of system catalogs.
*/
bool
dbms_stats_is_system_catalog_internal(Oid relid)
{
Relation rel;
char *schema_name;
bool result;
/* relid is InvalidOid */
if (!OidIsValid(relid))
return false;
/* no such relation */
rel = try_relation_open(relid, NoLock);
if (rel == NULL)
return false;
/* check by namespace name. */
schema_name = get_namespace_name(rel->rd_rel->relnamespace);
result = dbms_stats_is_system_schema_internal(schema_name);
relation_close(rel, NoLock);
return result;
}
/*
* dbms_stats_get_relation_info
* Hook function for get_relation_info_hook, which implements post-process of
* get_relation_info().
*
* This function is designed on the basis of the fact that only expression
* indexes have statistics.
*/
static void
dbms_stats_get_relation_info(PlannerInfo *root,
Oid relid,
bool inhparent,
RelOptInfo *rel)
{
ListCell *lc;
double allvisfrac; /* dummy */
/*
* Call previously installed hook function regardless to whether
* pg_dbms_stats is enabled or not.
*/
if (prev_get_relation_info)
prev_get_relation_info(root, relid, inhparent, rel);
/* If pg_dbms_stats is disabled, there is no more thing to do. */
if (!pg_dbms_stats_use_locked_stats)
return;
/*
* Adjust stats of table itself, and stats of index
* relation_stats_effective as well
*/
/*
* Estimate relation size --- unless it's an inheritance parent, in which
* case the size will be computed later in set_append_rel_pathlist, and we
* must leave it zero for now to avoid bollixing the total_table_pages
* calculation.
*/
if (!inhparent)
get_merged_relation_stats(relid, &rel->pages, &rel->tuples,
&rel->allvisfrac, true);
else
return;
foreach(lc, rel->indexlist)
{
/*
* Estimate the index size. If it's not a partial index, we lock
* the number-of-tuples estimate to equal the parent table; if it
* is partial then we have to use the same methods as we would for
* a table, except we can be sure that the index is not larger
* than the table.
*/
IndexOptInfo *info = (IndexOptInfo *) lfirst(lc);
bool estimate = info->indpred != NIL;
get_merged_relation_stats(info->indexoid, &info->pages, &info->tuples,
&allvisfrac, estimate);
if (!estimate || (estimate && info->tuples > rel->tuples))
info->tuples = rel->tuples;
}
}
/*
* dbms_stats_get_attavgwidth
* Hook function for get_attavgwidth_hook which replaces get_attavgwidth().
* Returning 0 tells caller to use standard routine.
*/
static int32
dbms_stats_get_attavgwidth(Oid relid, AttrNumber attnum)
{
if (pg_dbms_stats_use_locked_stats)
{
int32 width = get_merged_avgwidth(relid, attnum);
if (width > 0)
return width;
}
if (prev_get_attavgwidth)
return prev_get_attavgwidth(relid, attnum);
else
return 0;
}
/*
* We do nothing here, to keep the tuple valid even after examination.
*/
static void
FreeHeapTuple(HeapTuple tuple)
{
/* noop */
}
/*
* dbms_stats_get_relation_stats
* Hook function for get_relation_stats_hook which provides custom
* per-relation statistics.
* Returning false tells caller to use standard (true) statistics.
*/
static bool
dbms_stats_get_relation_stats(PlannerInfo *root,
RangeTblEntry *rte,
AttrNumber attnum,
VariableStatData *vardata)
{
if (pg_dbms_stats_use_locked_stats)
{
HeapTuple tuple;
tuple = get_merged_column_stats(rte->relid, attnum, rte->inh);
vardata->statsTuple = tuple;
if (HeapTupleIsValid(tuple))
{
vardata->freefunc = FreeHeapTuple;
#ifdef PGDS_HAVE_ACL_OK
/*
* set acl_ok if required. See the definition of set_acl_ok for
* details.
*/
if (set_acl_ok)
{
vardata->acl_ok =
(pg_class_aclcheck(rte->relid, GetUserId(),
ACL_SELECT) == ACLCHECK_OK) ||
(pg_attribute_aclcheck(rte->relid, attnum, GetUserId(),
ACL_SELECT) == ACLCHECK_OK);
}
#endif
return true;
}
}
if (prev_get_relation_stats)
return prev_get_relation_stats(root, rte, attnum, vardata);
else
return false;
}
/*
* dbms_stats_get_index_stats
* Hook function for get_index_stats_hook which provides custom per-relation
* statistics.
* Returning false tells caller to use standard (true) statistics.
*/
static bool
dbms_stats_get_index_stats(PlannerInfo *root,
Oid indexOid,
AttrNumber indexattnum,