diff options
Diffstat (limited to 'src/backend/optimizer/util/plancat.c')
| -rw-r--r-- | src/backend/optimizer/util/plancat.c | 67 |
1 files changed, 66 insertions, 1 deletions
diff --git a/src/backend/optimizer/util/plancat.c b/src/backend/optimizer/util/plancat.c index 463f8064678..cc88dcc28e4 100644 --- a/src/backend/optimizer/util/plancat.c +++ b/src/backend/optimizer/util/plancat.c @@ -29,6 +29,7 @@ #include "catalog/heap.h" #include "catalog/partition.h" #include "catalog/pg_am.h" +#include "catalog/pg_statistic_ext.h" #include "foreign/fdwapi.h" #include "miscadmin.h" #include "nodes/makefuncs.h" @@ -40,8 +41,11 @@ #include "parser/parse_relation.h" #include "parser/parsetree.h" #include "rewrite/rewriteManip.h" +#include "statistics/statistics.h" #include "storage/bufmgr.h" +#include "utils/builtins.h" #include "utils/lsyscache.h" +#include "utils/syscache.h" #include "utils/rel.h" #include "utils/snapmgr.h" @@ -63,7 +67,7 @@ static List *get_relation_constraints(PlannerInfo *root, bool include_notnull); static List *build_index_tlist(PlannerInfo *root, IndexOptInfo *index, Relation heapRelation); - +static List *get_relation_statistics(RelOptInfo *rel, Relation relation); /* * get_relation_info - @@ -398,6 +402,8 @@ get_relation_info(PlannerInfo *root, Oid relationObjectId, bool inhparent, rel->indexlist = indexinfos; + rel->statlist = get_relation_statistics(rel, relation); + /* Grab foreign-table info using the relcache, while we have it */ if (relation->rd_rel->relkind == RELKIND_FOREIGN_TABLE) { @@ -1251,6 +1257,65 @@ get_relation_constraints(PlannerInfo *root, return result; } +/* + * get_relation_statistics + * Retrieve extended statistics defined on the table. + * + * Returns a List (possibly empty) of StatisticExtInfo objects describing + * the statistics. Note that this doesn't load the actual statistics data, + * just the identifying metadata. Only stats actually built are considered. + */ +static List * +get_relation_statistics(RelOptInfo *rel, Relation relation) +{ + List *statoidlist; + List *stainfos = NIL; + ListCell *l; + + statoidlist = RelationGetStatExtList(relation); + + foreach(l, statoidlist) + { + Oid statOid = lfirst_oid(l); + Form_pg_statistic_ext staForm; + HeapTuple htup; + Bitmapset *keys = NULL; + int i; + + htup = SearchSysCache1(STATEXTOID, ObjectIdGetDatum(statOid)); + if (!htup) + elog(ERROR, "cache lookup failed for statistics %u", statOid); + staForm = (Form_pg_statistic_ext) GETSTRUCT(htup); + + /* + * First, build the array of columns covered. This is ultimately + * wasted if no stats are actually built, but it doesn't seem worth + * troubling over that case. + */ + for (i = 0; i < staForm->stakeys.dim1; i++) + keys = bms_add_member(keys, staForm->stakeys.values[i]); + + /* add one StatisticExtInfo for each kind built */ + if (statext_is_kind_built(htup, STATS_EXT_NDISTINCT)) + { + StatisticExtInfo *info = makeNode(StatisticExtInfo); + + info->statOid = statOid; + info->rel = rel; + info->kind = STATS_EXT_NDISTINCT; + info->keys = bms_copy(keys); + + stainfos = lcons(info, stainfos); + } + + ReleaseSysCache(htup); + bms_free(keys); + } + + list_free(statoidlist); + + return stainfos; +} /* * relation_excluded_by_constraints |