Re: collation, arrays, and ranges - Mailing list pgsql-hackers

From Tom Lane
Subject Re: collation, arrays, and ranges
Date
Msg-id 18979.1315675279@sss.pgh.pa.us
Whole thread Raw
In response to collation, arrays, and ranges  (Jeff Davis <pgsql@j-davis.com>)
Responses Re: collation, arrays, and ranges
List pgsql-hackers
Jeff Davis <pgsql@j-davis.com> writes:
> My interpretation of collation for range types is different than that
> for arrays, so I'm presenting it here in case someone has an objection.

> An array type has the same typcollation as its element type. This makes
> sense, because comparison between arrays are affected by the COLLATE
> clause.

> Comparison between ranges should not be affected by the COLLATE clause
> (as we discussed).

Check.

> So, I chose to represent that as a separate
> rngcollation and leave the typcollation 0. In other words, collation is
> a concept internal to that range type and fixed at type definition time.
> Range types are affected by their internal collation, but don't take
> part in the logic that passes collation through the type system.

Should I read that as saying you want to add yet another column to
pg_type?  I'd prefer not to do that.  Seems to me we could still store
the value in typcollation, but just interpret the column a bit
differently depending on typtype.
        regards, tom lane


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