Re: Bitmap index status

Hi Heikki,

Gavin and I are trying to merge our changes together this week. We will post
a new patch by the end of this week. This patch will include some style
fixes, bug fixes, and the stream bitmap implementation.

I will look into the problems you have mentioned in this email. Yes, vacuum
currently does a reindex now. Gavin and I just talked about this yesterday.
We are looking into ways to improve this. One way is not to do reindex for
each vacuum. We maintain a list of updated tids along with the bitmap index.
Only when this list goes to a certain point, vacuum will re-build the index.

Thanks,
Jie

On 9/12/06 2:43 AM, "Heikki Linnakangas" <heikki(at)enterprisedb(dot)com> wrote:

> Hi,
>
> What's the status of the bitmap index patch? Have you worked on it since
> the last posted patch
> (http://archives.postgresql.org/pgsql-patches/2006-08/msg00003.php)?
>
> I've started to review it, to get it into CVS early in the 8.3 cycle. I
> just want to make sure that I'm working on the latest version.
>
> Beside the issues already discussed, I found two minor bugs:
> * pg_am says that bitmap am supports unique indexes, while it doesn't.
> Second,
> * race condition in _bitmap_inserttuple if two backends try to insert
> the same, new value. If they both find that there's no lov item for the
> key, and try to create one, one backend will get a duplicate key error
> on the lov index.
>
> Also, vacuum actually does a reindex, which seems awfully wasteful. That
> needs to be looked at.