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.