Re: Unexpected page allocation behavior on insert-only tables
Tom Lane <tgl@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
To: Michael Renner <michael.renner@amd.co.at>
Cc: pgsql-hackers@postgresql.org
Date: 2010-05-16T00:16:47Z
Lists: pgsql-hackers
Michael Renner <michael.renner@amd.co.at> writes: > I've written a simple tool to generate traffic on a database [1], which > did about 30 TX/inserts per second to a table. Upon inspecting the data > in the table, I noticed the expected grouping of tuples which came from > a single backend to matching pages [2]. The strange part was that the > pages weren't completely filled but the backends seemed to jump > arbitrarily from one page to the next [3]. For the table in question > this resulted in about 10% wasted space. Which table would that be? The trigger-driven updates to "auction", in particular, would certainly guarantee some amount of "wasted" space. regards, tom lane