diff options
Diffstat (limited to 'src/backend/utils/adt/selfuncs.c')
| -rw-r--r-- | src/backend/utils/adt/selfuncs.c | 33 |
1 files changed, 25 insertions, 8 deletions
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c index 443647298eb..b7313687169 100644 --- a/src/backend/utils/adt/selfuncs.c +++ b/src/backend/utils/adt/selfuncs.c @@ -102,6 +102,7 @@ #include <math.h> #include "access/brin.h" +#include "access/brin_page.h" #include "access/gin.h" #include "access/htup_details.h" #include "access/sysattr.h" @@ -7879,11 +7880,31 @@ brincostestimate(PlannerInfo *root, IndexPath *path, double loop_count, &spc_seq_page_cost); /* - * Obtain some data from the index itself. + * Obtain some data from the index itself, if possible. Otherwise invent + * some plausible internal statistics based on the relation page count. */ - indexRel = index_open(index->indexoid, AccessShareLock); - brinGetStats(indexRel, &statsData); - index_close(indexRel, AccessShareLock); + if (!index->hypothetical) + { + indexRel = index_open(index->indexoid, AccessShareLock); + brinGetStats(indexRel, &statsData); + index_close(indexRel, AccessShareLock); + + /* work out the actual number of ranges in the index */ + indexRanges = Max(ceil((double) baserel->pages / + statsData.pagesPerRange), 1.0); + } + else + { + /* + * Assume default number of pages per range, and estimate the number + * of ranges based on that. + */ + indexRanges = Max(ceil((double) baserel->pages / + BRIN_DEFAULT_PAGES_PER_RANGE), 1.0); + + statsData.pagesPerRange = BRIN_DEFAULT_PAGES_PER_RANGE; + statsData.revmapNumPages = (indexRanges / REVMAP_PAGE_MAXITEMS) + 1; + } /* * Compute index correlation @@ -7984,10 +8005,6 @@ brincostestimate(PlannerInfo *root, IndexPath *path, double loop_count, baserel->relid, JOIN_INNER, NULL); - /* work out the actual number of ranges in the index */ - indexRanges = Max(ceil((double) baserel->pages / statsData.pagesPerRange), - 1.0); - /* * Now calculate the minimum possible ranges we could match with if all of * the rows were in the perfect order in the table's heap. |