Re: Concurrent VACUUM and ANALYZE

Jonah H. Harris wrote:
> On Mon, Jul 21, 2008 at 10:19 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> "Jonah H. Harris" <jonah.harris@gmail.com> writes:
>>> The case I'm looking at is a large table which requires a lazy vacuum,
>>> and a zero vacuum cost delay would cause too much I/O.  Yet, this
>>> table has enough insert/delete activity during a vacuum, that it
>>> requires a fairly frequent analysis to maintain proper plans.  I
>>> patched as mentioned above and didn't run across any unexpected
>>> issues; the only one expected was that mentioned by Alvaro.
>> I don't find this a compelling argument, at least not without proof that
>> the various vacuum-improvement projects already on the radar screen
>> (DSM-driven vacuum, etc) aren't going to fix your problem.
> 
> Is DSM going to be in 8.4?  The last I had heard, DSM+related
> improvements weren't close to being guaranteed for this release.  If
> it doesn't make it, waiting another year and a half for something
> easily fixed would be fairly unacceptable.  Should I provide a patch
> in the event that DSM doesn't make it?

For the immediate term, would it make sense for the ANALYZE to give up 
and simply return if a VACUUM was in progress?

At least that way a client that sees performance degrade quickly between 
vacuums can run the occasional preventative analyze without blocking 
completely on auto-vacuums.


Jeroen