On Sun, 2008-08-03 at 19:44 -0400, Tom Lane wrote: > Zdenek Kotala <[EMAIL PROTECTED]> writes: > > I found that _bt_split function calls PageGetTempPage, but next call is > > _bt_page_init which clear all contents anyway. Is there any reason to call > > PageGetTempPage instead of palloc? > > Not violating a perfectly good abstraction? > > I agree that PageGetTempPage isn't amazingly efficient, but internal > refactoring would halve its cost; and if you have some evidence that > there's a real performance issue then we could think about adjusting > the temp-page API to allow _bt_pageinit to be combined with it. But > I have a real problem with hacking up _bt_split so that it will call > PageRestoreTempPage on something it didn't get from PageGetTempPage. > > Considering the WAL and regular I/O that will be induced by a split, > I kinda doubt this is even worth worrying about anyway...
Improving this should help, since the existing page is write locked during _bt_split. The I/O won't happen at the point that these blocks are critical contention points. -- Simon Riggs www.2ndQuadrant.com PostgreSQL Training, Services and Support -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
