diff options
| author | Tomas Vondra | 2019-03-27 17:32:18 +0000 |
|---|---|---|
| committer | Tomas Vondra | 2019-03-27 17:32:18 +0000 |
| commit | 7300a699502fe5432b05fbc75baca534b080bebb (patch) | |
| tree | 2fa5740b9cf8363068e8a575ae569ca172ffb66a /src/include/nodes | |
| parent | 333ed246c6f351c4e8fe22c764b97793c4101b00 (diff) | |
Add support for multivariate MCV lists
Introduce a third extended statistic type, supported by the CREATE
STATISTICS command - MCV lists, a generalization of the statistic
already built and used for individual columns.
Compared to the already supported types (n-distinct coefficients and
functional dependencies), MCV lists are more complex, include column
values and allow estimation of much wider range of common clauses
(equality and inequality conditions, IS NULL, IS NOT NULL etc.).
Similarly to the other types, a new pseudo-type (pg_mcv_list) is used.
Author: Tomas Vondra
Reviewed-by: Dean Rasheed, David Rowley, Mark Dilger, Alvaro Herrera
Discussion: https://postgr.es/m/dfdac334-9cf2-2597-fb27-f0fb3753f435@2ndquadrant.com
Diffstat (limited to 'src/include/nodes')
| -rw-r--r-- | src/include/nodes/bitmapset.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/src/include/nodes/bitmapset.h b/src/include/nodes/bitmapset.h index 892410635b5..0c645628e55 100644 --- a/src/include/nodes/bitmapset.h +++ b/src/include/nodes/bitmapset.h @@ -87,6 +87,7 @@ extern Bitmapset *bms_difference(const Bitmapset *a, const Bitmapset *b); extern bool bms_is_subset(const Bitmapset *a, const Bitmapset *b); extern BMS_Comparison bms_subset_compare(const Bitmapset *a, const Bitmapset *b); extern bool bms_is_member(int x, const Bitmapset *a); +extern int bms_member_index(Bitmapset *a, int x); extern bool bms_overlap(const Bitmapset *a, const Bitmapset *b); extern bool bms_overlap_list(const Bitmapset *a, const struct List *b); extern bool bms_nonempty_difference(const Bitmapset *a, const Bitmapset *b); |