Re: New FSM patch

From: Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com>
To: Simon Riggs <simon(at)2ndQuadrant(dot)com>
Cc: PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: New FSM patch
Date: 2008-09-05 08:47:28
Message-ID: 48C0F220.30002@enterprisedb.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

Simon Riggs wrote:
> On Thu, 2008-09-04 at 11:07 +0300, Heikki Linnakangas wrote:
>> Scenario: The binary tree on a page is corrupt, so that the value of an
>> upper node is > Max(leftchild, rightchild).
>> Consequence: Searchers will notice the corruption while trying to
>> traverse down that path, and throw an elog(WARNING) in search_avail().
>> fsm_search will retry the search, and will in worst case go into an
>> infinite loop. That's obviously not good. We could automatically fix the
>> upper nodes of the tree, but that would wipe evidence that would be
>> useful in debugging.
>
> We probably need to break out of infinite loops, especially ones that
> output warning messages on each loop. :-)

Yep. I turned that warning into an error in the latest patch I just
posted elsewhere in this thread.

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Zdenek Kotala 2008-09-05 09:01:20 Re: Page layout footprint
Previous Message Heikki Linnakangas 2008-09-05 08:46:28 Re: New FSM allocation policy