Re: Per-column collation, proof of concept

On Thu, Jul 15, 2010 at 4:24 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> The problem with not doing that is it breaks hashing --- hash joins and
> hash aggregation being the real pain points.
>
> citext works around this in a rather klugy fashion by decreeing that two
> strings are equal iff their str_tolower() conversions are bitwise equal.
> So it can hash the str_tolower() representation.  But that's kinda slow
> and it fails in the general case anyhow, I think.

I think the general equivalent would be to call strxfrm and hash the
result of that.



-- 
greg