Re: Hot standby and b-tree killed items - Mailing list pgsql-hackers

From Alvaro Herrera
Subject Re: Hot standby and b-tree killed items
Date
Msg-id 20081221234031.GA8720@alvh.no-ip.org
Whole thread Raw
In response to Re: Hot standby and b-tree killed items  (Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>)
List pgsql-hackers
Heikki Linnakangas wrote:
> Alvaro Herrera wrote:
>> Heikki Linnakangas wrote:
>>> Gregory Stark wrote:
>>>> A vacuum being replayed -- even in a different database -- could trigger the
>>>> error. Or with the btree split issue, a data load -- again even in a different
>>>> database -- would be quite likely cause your SELECT to be killed.
>>> Hmm, I wonder if we should/could track the "latestRemovedXid" 
>>> separately  for each database. There's no reason why we need to kill 
>>> a read-only  query in database X when a table in database Y is 
>>> vacuumed.
>>
>> What about shared catalogs?
>
> True, vacuums on shared catalogs would affect read-only queries on all  
> databases.

Maybe it's possible to track latestRemovedXid for each database, and
additionally another counter that tracks vacuums on shared catalogs.

-- 
Alvaro Herrera                                http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support


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