Re: WIP: Deferrable unique constraints

On Tue, Jul 14, 2009 at 12:13:33PM -0700, Jeff Davis wrote:
> On Tue, 2009-07-14 at 13:29 -0500, Kenneth Marshall wrote:
> > I am looking at adding unique support to hash indexes for 8.5 and
> > they will definitely need to visit the heap.
> 
> Have you seen this patch?
> 
> http://archives.postgresql.org/message-id/1246840119.19547.126.camel@jdavis
> 
> This patch will support unique constraints for hash indexes as well.
> There may still be a use-case for specialized hash index unique
> constraints, similar to btree, but please follow the work to make sure
> that no work is wasted.
> 
> Also, I don't see a problem with using the same hacks in the hash index
> code as is used in the btree index code. If you see a better way, or if
> you think index AM changes would be useful to you as well, you should
> probably open that discussion.
> 
> I was trying to provide an alternative to an index AM API change,
> because I thought there might be some resistance to that. However, if
> there are multiple index AMs that can make use of it, there is a
> stronger case for an API change.
> 
> Regards,
>     Jeff Davis
> 

I will take a look at that patch. My thought was to use the same
process as the btree support for unique indexes since it has been
well tested and optimized.

Thanks,
Ken