Re: Index bloat problem?

Bill Chandler wrote:

>Mischa,
>
>Thanks. Yes, I understand that not having a large
>enough max_fsm_pages is a problem and I think that it
>is most likely the case for the client. What I wasn't
>sure of was if the index bloat we're seeing is the
>result of the "bleeding" you're talking about or
>something else.
>
>If I deleted 75% of the rows but had a max_fsm_pages
>setting that still exceeded the pages required (as
>indicated in VACUUM output), would that solve my
>indexing problem or would I still need to REINDEX
>after such a purge?
>
>regards,
>
>Bill
>
>
I don't believe VACUUM re-packs indexes. It just removes empty index
pages. So if you have 1000 index pages all with 1 entry in them, vacuum
cannot reclaim any pages. REINDEX re-packs the pages to 90% full.

fsm just needs to hold enough pages that all requests have free space
that can be used before your next vacuum. It is just a map letting
postgres know where space is available for a new fill.

John
=:->