From 8224de4f42ccf98e08db07b43d52fed72f962ebb Mon Sep 17 00:00:00 2001 From: Teodor Sigaev Date: Sat, 7 Apr 2018 23:00:39 +0300 Subject: 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 --- src/backend/access/gist/gist.c | 1 + 1 file changed, 1 insertion(+) (limited to 'src/backend/access/gist/gist.c') diff --git a/src/backend/access/gist/gist.c b/src/backend/access/gist/gist.c index 52c83b9cbf5..9007d65ad2a 100644 --- a/src/backend/access/gist/gist.c +++ b/src/backend/access/gist/gist.c @@ -74,6 +74,7 @@ gisthandler(PG_FUNCTION_ARGS) amroutine->amclusterable = true; amroutine->ampredlocks = true; amroutine->amcanparallel = false; + amroutine->amcaninclude = false; amroutine->amkeytype = InvalidOid; amroutine->ambuild = gistbuild; -- cgit v1.2.3