diff options
| author | Teodor Sigaev | 2018-04-07 20:00:39 +0000 |
|---|---|---|
| committer | Teodor Sigaev | 2018-04-07 20:00:39 +0000 |
| commit | 8224de4f42ccf98e08db07b43d52fed72f962ebb (patch) | |
| tree | 0c4aae878e522178def568fcd2dd274233780f88 /src/include/utils | |
| parent | 01bb85169afadfe63e2f0e344ff671292080de7e (diff) | |
Indexes with INCLUDE columns and their support in B-tree
This patch introduces INCLUDE clause to index definition. This clause
specifies a list of columns which will be included as a non-key part in
the index. The INCLUDE columns exist solely to allow more queries to
benefit from index-only scans. Also, such columns don't need to have
appropriate operator classes. Expressions are not supported as INCLUDE
columns since they cannot be used in index-only scans.
Index access methods supporting INCLUDE are indicated by amcaninclude flag
in IndexAmRoutine. For now, only B-tree indexes support INCLUDE clause.
In B-tree indexes INCLUDE columns are truncated from pivot index tuples
(tuples located in non-leaf pages and high keys). Therefore, B-tree indexes
now might have variable number of attributes. This patch also provides
generic facility to support that: pivot tuples contain number of their
attributes in t_tid.ip_posid. Free 13th bit of t_info is used for indicating
that. This facility will simplify further support of index suffix truncation.
The changes of above are backward-compatible, pg_upgrade doesn't need special
handling of B-tree indexes for that.
Bump catalog version
Author: Anastasia Lubennikova with contribition by Alexander Korotkov and me
Reviewed by: Peter Geoghegan, Tomas Vondra, Antonin Houska, Jeff Janes,
David Rowley, Alexander Korotkov
Discussion: https://www.postgresql.org/message-id/flat/56168952.4010101@postgrespro.ru
Diffstat (limited to 'src/include/utils')
| -rw-r--r-- | src/include/utils/rel.h | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/src/include/utils/rel.h b/src/include/utils/rel.h index 9826c67fc41..ffffde01da9 100644 --- a/src/include/utils/rel.h +++ b/src/include/utils/rel.h @@ -438,11 +438,25 @@ typedef struct ViewOptions /* * RelationGetNumberOfAttributes - * Returns the number of attributes in a relation. + * Returns the total number of attributes in a relation. */ #define RelationGetNumberOfAttributes(relation) ((relation)->rd_rel->relnatts) /* + * IndexRelationGetNumberOfAttributes + * Returns the number of attributes in an index. + */ +#define IndexRelationGetNumberOfAttributes(relation) \ + ((relation)->rd_index->indnatts) + +/* + * IndexRelationGetNumberOfKeyAttributes + * Returns the number of key attributes in an index. + */ +#define IndexRelationGetNumberOfKeyAttributes(relation) \ + ((relation)->rd_index->indnkeyatts) + +/* * RelationGetDescr * Returns tuple descriptor for a relation. */ |