diff options
| author | Alvaro Herrera | 2017-04-06 20:49:26 +0000 |
|---|---|---|
| committer | Alvaro Herrera | 2017-04-06 20:51:53 +0000 |
| commit | 7e534adcdc70866e7be74d626b0ed067c890a251 (patch) | |
| tree | 609e0b65eb10538fdaa787fc29dee9655a6da710 /src/include | |
| parent | b2ff37d43cc81348fd8e9d9c5fcc9dfadf790763 (diff) | |
Fix BRIN cost estimation
The original code was overly optimistic about the cost of scanning a
BRIN index, leading to BRIN indexes being selected when they'd be a
worse choice than some other index. This complete rewrite should be
more accurate.
Author: David Rowley, based on an earlier patch by Emre Hasegeli
Reviewed-by: Emre Hasegeli
Discussion: https://postgr.es/m/CAKJS1f9n-Wapop5Xz1dtGdpdqmzeGqQK4sV2MK-zZugfC14Xtw@mail.gmail.com
Diffstat (limited to 'src/include')
| -rw-r--r-- | src/include/access/brin.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/src/include/access/brin.h b/src/include/access/brin.h index 3f4c29bdcb5..e03aa08f608 100644 --- a/src/include/access/brin.h +++ b/src/include/access/brin.h @@ -25,6 +25,17 @@ typedef struct BrinOptions bool autosummarize; } BrinOptions; + +/* + * BrinStatsData represents stats data for planner use + */ +typedef struct BrinStatsData +{ + BlockNumber pagesPerRange; + BlockNumber revmapNumPages; +} BrinStatsData; + + #define BRIN_DEFAULT_PAGES_PER_RANGE 128 #define BrinGetPagesPerRange(relation) \ ((relation)->rd_options ? \ @@ -35,4 +46,7 @@ typedef struct BrinOptions ((BrinOptions *) (relation)->rd_options)->autosummarize : \ false) + +extern void brinGetStats(Relation index, BrinStatsData *stats); + #endif /* BRIN_H */ |