Re: Re: significant performance hit whenever autovacuum runs after upgrading from 9.0 -> 9.1

On Mon, May 21, 2012 at 2:05 PM, Lonni J Friedman<netllama@gmail.com>  wrote:
>> Greetings,
>> When I got in this morning, I found
>> an autovacuum process that had been running since just before the load
>> spiked,

Autovacuum might need to set the freeze bit very first time it runs.  I recall hearing advice about running a 'vacuum
freeze'after you insert a huge amount of data.  And I recall pg_upgrade doesn't write stats, so did you analyze your
database?

Or, maybe its not vacuum... maybe some of your sql statements are planning differently and running really bad.  Can you
checksome?  Can you log slow queries? 

Have you checked the status of your raid?  Maybe you lost a drive and its in recovery and you have very slow IO?

-Andy