pgsql: Reduce the initial size of local lock hash to 16 entries. - Mailing list pgsql-committers

From Heikki Linnakangas
Subject pgsql: Reduce the initial size of local lock hash to 16 entries.
Date
Msg-id E1QAhoS-0000wd-8B@gemulon.postgresql.org
Whole thread Raw
List pgsql-committers
Reduce the initial size of local lock hash to 16 entries.

The hash table is seq scanned at transaction end, to release all locks,
and making the hash table larger than necessary makes that slower. With
very simple queries, that overhead can amount to a few percent of the total
CPU time used.

At the moment, backend startup needs 6 locks, and a simple query with one
table and index needs 3 locks. 16 is enough for even quite complicated
transactions, and it will grow automatically if it fills up.

Branch
------
master

Details
-------
http://git.postgresql.org/pg/commitdiff/4c37c1e3b2a7ba7b5519e5e366720e7444878a78

Modified Files
--------------
src/backend/storage/lmgr/lock.c |    2 +-
1 files changed, 1 insertions(+), 1 deletions(-)


pgsql-committers by date:

Previous
From: dpage@pgfoundry.org (Dave Page)
Date:
Subject: pginstaller - pginst: Update for 8.3.15
Next
From: Magnus Hagander
Date:
Subject: pgsql: Note that Bison on GnuWin32 has trouble with paths with spaces