Re: Perfomance decreasing

Tom Lane wrote:

> >> I'm  doing  vacuum  periodically  (once a hour), but perfomance
> >> still falls down.
>
> It sounds to me like you may be running into index growth problems.
> VACUUM is presently not good about shrinking indexes.

I always enjoy Tom's comments - he is the master of understatement and always helpful.

In this case, however, I think he may be understating too much.  I read the original question as "PostgreSQL is not useful for production systems."  Call me melodramatic if you like: you are probably right.

The point, I guess, is this: it would be really useful to have a document somewhere that honestly described the limitations of (the current version of) PostgreSQL.  Don't use inheritance, don't use on 24x7 systems, whatever.  It doesn't have to be fancy formatting, a brain-dump to a text file would be excellent....  (This is a hint, Tom et al!! :-))

>  If you drop
> and recreate the indexes used by your most important queries, does
> the performance go back to where it was?

For what it's worth: I observed a similar issue and found that a dump and restore of all the databases helped.  I haven't tried just recreating the index.  I'll try it out and maybe post a test script to reproduce the issue..... (where?)


    --- Allan.