#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"
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. */
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"
/*
* 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.
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);
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);
HeapTuple tuple);
static bool execute_plan(SPIPlanPtr *plan, const char *query, Oid relid,
const AttrNumber *attnum, bool inh);
-static void StatsCacheRelCallback(Datum arg, Oid relid);
+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,
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(StatsCacheRelCallback, (Datum) 0);
+ CacheRegisterRelcacheCallback(statscache_rel_callback, (Datum) 0);
}
/*
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. */
}
/*
* scan over simple_rel_array_size to find the owner relation of the
- * index that its oid is indexOid
+ * index with the oid
*/
for (i = 1 ; i < root->simple_rel_array_size ; i++)
{
return false;
}
+
+/*
+ * dbms_stats_planner
+ * Hook function for planner_hook which cleans up invalidated statistics.
+ */
+static PlannedStmt *
+dbms_stats_planner(Query *parse, int cursorOptions, ParamListInfo boundParams)
+{
+ PlannedStmt *ret;
+
+ cleanup_invalidated_cache();
+
+ if (prev_planner_hook)
+ ret = (*prev_planner_hook) (parse, cursorOptions, boundParams);
+ else
+ ret = standard_planner(parse, cursorOptions, boundParams);
+
+ cleanup_invalidated_cache();
+
+ return ret;
+}
+
+
/*
* Extract binary value from given column.
*/
}
/*
- * StatsCacheRelCallback
+ * statscache_rel_callback
* Relcache inval callback function
*
- * Invalidate cached statistic info of the given relid, or all cached statistic
- * info if relid == InvalidOid. We don't complain even when we don't have such
- * statistics.
+ * Invalidates cached statistics of the given relid, or all cached statistics
+ * if relid == InvalidOid. The statsTuple in the hash entries are directly
+ * passed to planner so we cannot remove them until planner ends. Just mark
+ * here then cleanup after planner finishes work.
+ */
+static void
+statscache_rel_callback(Datum arg, Oid relid)
+{
+ StatsRelationEntry *entry;
+
+ if (relid != InvalidOid)
+ {
+ bool found;
+
+ /*
+ * invalidate the entry for the specfied relation. Don't mind if found.
+ */
+ entry = hash_search(rel_stats, &relid, HASH_FIND, &found);
+ if (found)
+ {
+ entry->invalidated = true;
+ rel_invalidated = true;
+ }
+ }
+ else
+ {
+ /* invalidate all the entries of the hash */
+ HASH_SEQ_STATUS status;
+
+ hash_seq_init(&status, rel_stats);
+ while ((entry = hash_seq_search(&status)) != NULL)
+ {
+ entry->invalidated = true;
+ rel_invalidated = true;
+ }
+ }
+}
+
+/*
+ * cleanup_invalidated_cache()
+ * Cleanup invalidated stats cache
*
- * Note: arg is not used.
+ * removes invalidated cache entries.
*/
static void
-StatsCacheRelCallback(Datum arg, Oid relid)
+cleanup_invalidated_cache(void)
{
HASH_SEQ_STATUS status;
StatsRelationEntry *entry;
+ /* Return immediately if nothing to do */
+ if (!rel_invalidated)
+ return;
+
+ /*
+ * Reset rel_invalidated first so that we don't lose invalidations that
+ * happens during this round of cleanup.
+ */
+ rel_invalidated = false;
+
hash_seq_init(&status, rel_stats);
while ((entry = hash_seq_search(&status)) != NULL)
{
- if (relid == InvalidOid || relid == entry->relid)
- {
- ListCell *lc;
+ ListCell *lc;
- /* Mark the relation entry as INVALID */
- entry->valid = false;
+ if (!entry->invalidated)
+ continue;
- /* Discard every column statistics */
- foreach (lc, entry->col_stats)
- {
- StatsColumnEntry *ent = (StatsColumnEntry*) lfirst(lc);
+ /* Discard every column statistics */
+ foreach (lc, entry->col_stats)
+ {
+ StatsColumnEntry *ent = (StatsColumnEntry*) lfirst(lc);
- if (!ent->negative)
- pfree(ent->tuple);
- pfree(ent);
- }
- list_free(entry->col_stats);
- entry->col_stats = NIL;
+ if (!ent->negative)
+ pfree(ent->tuple);
+ pfree(ent);
}
- }
+ list_free(entry->col_stats);
- /* We always check throughout the list, so hash_seq_term is not necessary */
+ /* Finally remove the hash entry. */
+ hash_search(rel_stats, &entry->relid, HASH_REMOVE, NULL);
+ }
}
/*
{
entry->relid = relid;
entry->valid = false;
+ entry->invalidated = false;
entry->relpages = InvalidBlockNumber;
entry->reltuples = 0.0;
entry->relallvisible = InvalidBlockNumber;
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