Re: cost-based vacuum

On Tue, 2005-07-12 at 13:50 -0400, Ian Westmacott wrote:
> It appears not to matter whether it is one of the tables
> being written to that is ANALYZEd.  I can ANALYZE an old,
> quiescent table, or a system table and see this effect.

Can you confirm that this effect is still seen even when the ANALYZE
doesn't touch *any* of the tables being accessed?

> - this is a dual Xeon.

Is that Xeon MP then?

> - Looking at oprofile reports for 10-minute runs of a
>   database-wide VACUUM with vacuum_cost_delay=0 and 1000,
>   shows the latter spending a lot of time in LWLockAcquire
>   and LWLockRelease (20% each vs. 2%).

Is this associated with high context switching also?

Best Regards, Simon Riggs