From: | Robert Haas <robertmhaas(at)gmail(dot)com> |
---|---|
To: | pgsql-hackers(at)postgresql(dot)org |
Subject: | heap_page_prune comments |
Date: | 2011-11-02 16:27:02 |
Message-ID: | CA+TgmoaFjJ57B-RBG-RxE9XMXgXvySns0q8_ujW5CfXM76vgwA@mail.gmail.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
The following comment - or at least the last sentence thereof -
appears to be out of date.
/*
* XXX Should we update the FSM information of this page ?
*
* There are two schools of thought here. We may not want to update FSM
* information so that the page is not used for unrelated
UPDATEs/INSERTs
* and any free space in this page will remain available for further
* UPDATEs in *this* page, thus improving chances for doing HOT updates.
*
* But for a large table and where a page does not receive
further UPDATEs
* for a long time, we might waste this space by not updating the FSM
* information. The relation may get extended and fragmented further.
*
* One possibility is to leave "fillfactor" worth of space in this page
* and update FSM with the remaining space.
*
* In any case, the current FSM implementation doesn't accept
* one-page-at-a-time updates, so this is all academic for now.
*/
The simple fix here is just to delete that last sentence, but does
anyone think we ought to do change the behavior, now that we have the
option to do so?
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
From | Date | Subject | |
---|---|---|---|
Next Message | Simon Riggs | 2011-11-02 16:34:11 | Re: pgsql: Reduce checkpoints and WAL traffic on low activity database serv |
Previous Message | Dimitri Fontaine | 2011-11-02 16:25:00 | Re: DeArchiver process |