Re: analyze after a database restore?

[Rod Taylor <rbt(at)rbt(dot)ca>]

On Thu, 2003-02-27 at 12:27, mlw wrote:
> I just dumped and restored a rather large database, I upgraded from 
> 7.2.x to 7.3.x. When I went to test my application against the new 
> database, it was dog slow. It had all the indexes, and looked fine.
> 
> Then it dawned on me, Doh! ANALYZE!
> 
> Should pg_dump appened an ANALYZE for each table?
> 
> On small tables, this shouldn't take too long. On large tables, you're 
> gonna have to do it anyway. I guess it could be an option as well.
> 
> It just seems like on of the tasks that is required for a "restored" 
> database to work properly, and as such, should probably be specified in 
> the backup procedure.

It's been debated before whether pg_dump should append ANALYZE to the
end of the load script.  It has always been determined that it shouldn't
(see archives for arguments).

However, an 'Auto-vacuum' process should watch stats and re-analyze the
table when the larger of 30% or 1000 rows has been affected (inserts, or
deletes mostly). That is probably a better solution overall.

-- 
Rod Taylor <rbt(at)rbt(dot)ca>

PGP Key: http://www.rbt.ca/rbtpub.asc

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