Re: Index-only quals

I added this URL to the existing TODO item.

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Heikki Linnakangas wrote:
> Here is an updated version of my patch to return data from b-tree
> indexes, and use it to satisfy quals.
> 
> I added a new column 'amregurgitate' to pg_am, to mark which indexams
> can return index tuples. Also, the data type of the index column in
> pg_attribute must match the type of the heap column - this catches the
> hack that 'name' is stored as cstring, that I had hardcoded before.
> 
> As discussed, GiST/GIN would need more infrastructure to mark which
> opclasses can return tuples, but as long as GiST/GIN doesn't support
> regurgitation at all, I'm not going to complicate the catalogs with that.
> 
> There's also some planner fixes - indexes that are only useful because
> of index-only quals are not considered for bitmap scans, and volatile
> expressions mustn't be used as index-only quals.
> 
> 
> This patch comes in two parts. Indexam API changes, which just splits
> the indexam_getnext function into two without providing any new
> functionality, and the main patch that applies on top of the indexam API
> changes. The patches are also available at
> git://git.postgresql.org/git/users/heikki/postgres.git, branches
> 'indexam-api-changes and 'indexfilter'.
> 
> Barring objections, I'm going to apply the indexam API changes part,
> since that simplifies the code in question regardless of the rest of the
> work. I'm pretty happy now with the indexfilter patch as well, but want
> to do some more testing on that before committing. Some more eyeballs
> would be appreciated as well.
> 
> -- 
>   Heikki Linnakangas
>   EnterpriseDB   http://www.enterprisedb.com



> 
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