Re: Further pg_upgrade analysis for many tables
Tom Lane <tgl@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Stephen Frost <sfrost@snowman.net>
Cc: Jeff Janes <jeff.janes@gmail.com>, Simon Riggs <simon@2ndquadrant.com>, Bruce Momjian <bruce@momjian.us>, PostgreSQL-development <pgsql-hackers@postgresql.org>, Magnus Hagander <magnus@hagander.net>
Date: 2013-01-20T19:32:29Z
Lists: pgsql-hackers
Stephen Frost <sfrost@snowman.net> writes: > I'm curious if this is going to help with rollback's of transactions > which created lots of tables..? We've certainly seen that take much > longer than we'd like, although I've generally attributed it to doing > all of the unlink'ing and truncating of files. If a single transaction creates lots of tables and then rolls back, this patch won't change anything because we'll long since have overflowed the eoxact list. But you weren't seeing an O(N^2) penalty in such cases anyway: that penalty came from doing O(N) work in each of N transactions. I'm sure you're right that you're mostly looking at the filesystem cleanup work, which we can't do much about. regards, tom lane