database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-12-16 16:42:29 +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

20
src/test/regress/sql/create_index.sql
View File

@@ -741,6 +741,26 @@ INSERT INTO func_index_heap VALUES('ABCD', 'EF');
-- but this shouldn't:
INSERT INTO func_index_heap VALUES('QWERTY');
--
-- Test unique index with included columns
--
CREATE TABLE covering_index_heap (f1 int, f2 int, f3 text);
CREATE UNIQUE INDEX covering_index_index on covering_index_heap (f1,f2) INCLUDE(f3);
INSERT INTO covering_index_heap VALUES(1,1,'AAA');
INSERT INTO covering_index_heap VALUES(1,2,'AAA');
-- this should fail because of unique index on f1,f2:
INSERT INTO covering_index_heap VALUES(1,2,'BBB');
-- and this shouldn't:
INSERT INTO covering_index_heap VALUES(1,4,'AAA');
-- Try to build index on table that already contains data
CREATE UNIQUE INDEX covering_pkey on covering_index_heap (f1,f2) INCLUDE(f3);
-- Try to use existing covering index as primary key
ALTER TABLE covering_index_heap ADD CONSTRAINT covering_pkey PRIMARY KEY USING INDEX
covering_pkey;
DROP TABLE covering_index_heap;
--
-- Also try building functional, expressional, and partial indexes on
-- tables that already contain data.