Re: Vacuum Blocking A Deleteion - Why? - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Vacuum Blocking A Deleteion - Why?
Date
Msg-id 8624.1136413034@sss.pgh.pa.us
Whole thread Raw
In response to Vacuum Blocking A Deleteion - Why?  (Brad Nicholson <bnichols@ca.afilias.info>)
List pgsql-hackers
Brad Nicholson <bnichols@ca.afilias.info> writes:
> We have been having a problem with a long running vacuum on a table 
> blocking deletes.  We have a log table on which the only activity is an 
> on going series of deletions.  The problem is experienced on a slony 
> replicated node, but I don't  think that slony is at fault here.

> My question - why is a vacuum blocking a deletion?

The problem is evidently that it's got an exclusive lock on the table:

>     17578 | 1744920 | AccessExclusiveLock      | t

which is entirely unexpected behavior for plain VACUUM in any release
later than 7.1.  I have to think that slony does have something to do
with it ... would suggest asking the slony folk about this.
        regards, tom lane


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