Re: WIP patch: Collation support

On Fri, Sep 19, 2008 at 10:13:43AM +0300, Heikki Linnakangas wrote:
> In addition to catalog changes, for finer grained collation you need
> changes in the planner and executor as well. In planner, to provide
> support for the concept of a sort order using a specific collation, and
> track that whenever sort order is handled. In executor, the capability
> to compare and sort using different locales at different times. Those
> changes seem a lot more difficult to me than adding a couple of system
> catalogs, which is pretty straightforward.

To be honest, I think that's the easy part. When I submitted the
collate patch a few years back, getting the sort order working was the
easy part, precisely because COLLATE clauses can affect the generated
plan in precisely one way: can you use index FOO or not. Once you're
past that point you can throw almost all the collation information
away.

As you point out though, the shear volume of catalog changes required
obscure that fact somewhat.

> It's not like the patch is going to disappear from planet Earth if it
> doesn't get committed for 8.4. It's still valuable and available when
> the new catalogs are needed.

I just prefer it as it was because it takes care of a useful subset of
the features people want in a way that is compatable for the future.
Whereas the stripped down version, I'm not sure it gets us anywhere.

Have a nice day,
--
Martijn van Oosterhout <kleptog(at)svana(dot)org> http://svana.org/kleptog/
> Please line up in a tree and maintain the heap invariant while
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