Re: crash on 8.2 and cvshead - failed to add item to the - Mailing list pgsql-hackers

From Heikki Linnakangas
Subject Re: crash on 8.2 and cvshead - failed to add item to the
Date
Msg-id 45C0738D.10204@enterprisedb.com
Whole thread Raw
In response to Re: crash on 8.2 and cvshead - failed to add item to the  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
Tom Lane wrote:
> Are you still concerned about the PageGetFreeSpace issue?

Not anymore.

The failure case I had in mind was not being able to find any valid 
split points when a page is full of max-sized index tuples. On a closer 
look, that doesn't seem to be a problem. Even though checksplitloc would 
incorrectly consider the split (HIKEY+item)-(HIKEY+item+item) as 
invalid, the split (HIKEY+item+item)-(HIKEY+item) is just as good. 
Similarly on the rightmost page, even if (HIKEY+item)-(item+item+item) 
is incorrectly considered as invalid, (HIKEY+item+item)-(item+item) is fine.

There also seems to always be some slack space because of alignments.

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


pgsql-hackers by date:

Previous
From: Magnus Hagander
Date:
Subject: Re: [BUGS] Missing error message on missing ssl-key-files
Next
From: "Pavan Deolasee"
Date:
Subject: Re: stack usage in toast_insert_or_update()