diff options
Diffstat (limited to 'src/backend/optimizer/util')
| -rw-r--r-- | src/backend/optimizer/util/plancat.c | 30 | ||||
| -rw-r--r-- | src/backend/optimizer/util/relnode.c | 2 |
2 files changed, 29 insertions, 3 deletions
diff --git a/src/backend/optimizer/util/plancat.c b/src/backend/optimizer/util/plancat.c index 0b3675f1461..aa436004f89 100644 --- a/src/backend/optimizer/util/plancat.c +++ b/src/backend/optimizer/util/plancat.c @@ -116,7 +116,7 @@ get_relation_info(PlannerInfo *root, Oid relationObjectId, bool inhparent, */ if (!inhparent) estimate_rel_size(relation, rel->attr_widths - rel->min_attr, - &rel->pages, &rel->tuples); + &rel->pages, &rel->tuples, &rel->allvisfrac); /* * Make list of indexes. Ignore indexes on system catalogs if told to. @@ -339,8 +339,10 @@ get_relation_info(PlannerInfo *root, Oid relationObjectId, bool inhparent, } else { + double allvisfrac; /* dummy */ + estimate_rel_size(indexRelation, NULL, - &info->pages, &info->tuples); + &info->pages, &info->tuples, &allvisfrac); if (info->tuples > rel->tuples) info->tuples = rel->tuples; } @@ -369,17 +371,21 @@ get_relation_info(PlannerInfo *root, Oid relationObjectId, bool inhparent, /* * estimate_rel_size - estimate # pages and # tuples in a table or index * + * We also estimate the fraction of the pages that are marked all-visible in + * the visibility map, for use in estimation of index-only scans. + * * If attr_widths isn't NULL, it points to the zero-index entry of the * relation's attr_widths[] cache; we fill this in if we have need to compute * the attribute widths for estimation purposes. */ void estimate_rel_size(Relation rel, int32 *attr_widths, - BlockNumber *pages, double *tuples) + BlockNumber *pages, double *tuples, double *allvisfrac) { BlockNumber curpages; BlockNumber relpages; double reltuples; + BlockNumber relallvisible; double density; switch (rel->rd_rel->relkind) @@ -432,11 +438,13 @@ estimate_rel_size(Relation rel, int32 *attr_widths, if (curpages == 0) { *tuples = 0; + *allvisfrac = 0; break; } /* coerce values in pg_class to more desirable types */ relpages = (BlockNumber) rel->rd_rel->relpages; reltuples = (double) rel->rd_rel->reltuples; + relallvisible = (BlockNumber) rel->rd_rel->relallvisible; /* * If it's an index, discount the metapage while estimating the @@ -480,21 +488,37 @@ estimate_rel_size(Relation rel, int32 *attr_widths, density = (BLCKSZ - SizeOfPageHeaderData) / tuple_width; } *tuples = rint(density * (double) curpages); + + /* + * We use relallvisible as-is, rather than scaling it up like we + * do for the pages and tuples counts, on the theory that any + * pages added since the last VACUUM are most likely not marked + * all-visible. But costsize.c wants it converted to a fraction. + */ + if (relallvisible == 0 || curpages <= 0) + *allvisfrac = 0; + else if ((double) relallvisible >= curpages) + *allvisfrac = 1; + else + *allvisfrac = (double) relallvisible / curpages; break; case RELKIND_SEQUENCE: /* Sequences always have a known size */ *pages = 1; *tuples = 1; + *allvisfrac = 0; break; case RELKIND_FOREIGN_TABLE: /* Just use whatever's in pg_class */ *pages = rel->rd_rel->relpages; *tuples = rel->rd_rel->reltuples; + *allvisfrac = 0; break; default: /* else it has no disk storage; probably shouldn't get here? */ *pages = 0; *tuples = 0; + *allvisfrac = 0; break; } } diff --git a/src/backend/optimizer/util/relnode.c b/src/backend/optimizer/util/relnode.c index 1df727d9fc8..37187e20735 100644 --- a/src/backend/optimizer/util/relnode.c +++ b/src/backend/optimizer/util/relnode.c @@ -109,6 +109,7 @@ build_simple_rel(PlannerInfo *root, int relid, RelOptKind reloptkind) rel->indexlist = NIL; rel->pages = 0; rel->tuples = 0; + rel->allvisfrac = 0; rel->subplan = NULL; rel->subroot = NULL; rel->baserestrictinfo = NIL; @@ -362,6 +363,7 @@ build_join_rel(PlannerInfo *root, joinrel->indexlist = NIL; joinrel->pages = 0; joinrel->tuples = 0; + joinrel->allvisfrac = 0; joinrel->subplan = NULL; joinrel->subroot = NULL; joinrel->baserestrictinfo = NIL; |