database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-11-19 13:42:17 +03:00
Code Activity

Indexes with INCLUDE columns and their support in B-tree

Browse Source 
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
This commit is contained in:
Teodor Sigaev
2018-04-07 23:00:39 +03:00
parent 01bb85169a
commit 8224de4f42
89 changed files with 2112 additions and 467 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
src/backend/utils/sort/tuplesort.c
View File

@@ -900,7 +900,7 @@ tuplesort_begin_cluster(TupleDesc tupDesc,
workMem, randomAccess ? 't' : 'f');
#endif
state->nKeys = RelationGetNumberOfAttributes(indexRel);
state->nKeys = IndexRelationGetNumberOfKeyAttributes(indexRel);
TRACE_POSTGRESQL_SORT_START(CLUSTER_SORT,
false, /* no unique check */
@@ -995,7 +995,7 @@ tuplesort_begin_index_btree(Relation heapRel,
workMem, randomAccess ? 't' : 'f');
#endif
state->nKeys = RelationGetNumberOfAttributes(indexRel);
state->nKeys = IndexRelationGetNumberOfKeyAttributes(indexRel);
TRACE_POSTGRESQL_SORT_START(INDEX_SORT,
enforceUnique,
@@ -1015,7 +1015,6 @@ tuplesort_begin_index_btree(Relation heapRel,
state->enforceUnique = enforceUnique;
indexScanKey = _bt_mkscankey_nodata(indexRel);
state->nKeys = RelationGetNumberOfAttributes(indexRel);
/* Prepare SortSupport data for each column */
state->sortKeys = (SortSupport) palloc0(state->nKeys *