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Re: Nasty btree deletion bug

From: "Heikki Linnakangas" <heikki(at)enterprisedb(dot)com>
To: "Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Nasty btree deletion bug
Date: 2006-10-26 17:08:10
Message-ID: 4540EB7A.2080201@enterprisedb.com (view raw or flat)
Thread:
Lists: pgsql-hackers
Tom Lane wrote:
> On further reflection, I think I understand why we've not realized the
> existence of this bug before: in fact, it *doesn't* lead to wrong search
> answers.  I think the only visible consequence is exactly the "failed to
> re-find parent key" VACUUM error that Ed saw.  The reason is that the
> key misordering in the grandparent level is nearly harmless.  Using your
> example of

Yep. It's pretty harmless.

But now that I look at the original post by Ed, I don't see how the 
"failed to re-find parent key" error could result from the issue we've 
been talking about. The error message is printed when _bt_getstackbuf is 
unable to re-find an item in the parent of a deleted page, but 
_bt_getstackbuf doesn't look at or compare the keys at all.

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

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Subject: Re: Nasty btree deletion bug
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