Re: FSM, now without WAL-logging

Tom Lane wrote:
> Heikki Linnakangas <heikki.linnakangas@enterprisedb.com> writes:
>> Zdenek Kotala wrote:
>>> What's about truncate FSM during WAL replay of main fork truncation record?
> 
>> That would work, except that there's no WAL record for truncating the
>> main fork.
> 
> Whaddya mean there's no WAL record for that?  smgrtruncate produces one.

Ooh, I didn't realize that!

Hmm. The smgrtuncate WAL record is generated after the file is 
truncated, so there's still a small window there, where we can be left 
with a truncated main fork, but no smgrtruncate record for it, and thus 
the page of the FSM representing the truncated blocks doesn't get zeroed 
at replay.

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