Re: Hashable custom types

From: Atri Sharma <atri(dot)jiit(at)gmail(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: David Fetter <david(at)fetter(dot)org>, Paul Ramsey <pramsey(at)cleverelephant(dot)ca>, Pgsql Hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Hashable custom types
Date: 2014-04-26 17:39:15
Message-ID: CAOeZVieerp78uDL6on9XSJygciUway9cHDmCOmoxir0nsPuSLw@mail.gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

The plain UNION code supports either sorting or hashing, but
> we've not gotten around to supporting a sort-based approach
> to recursive UNION. I'm not convinced that it's worth doing ...
>
> regards, tom lane
>
>
>
Without sorting, isnt the scope of a recursive UNION with custom datatypes
pretty restrictive?

As is, even the sorting shall be a bit restrictive due to the costs
associated. I feel what David has suggested upthread should be good. Maybe
an experimental patch with a workload that should give a load factor 1 for
the hash table should prove some performance points.

Even if thats not the case, we should really do something to improve the
scope of usability of recursive UNION with custom types.

Regards,

Atri

--
Regards,

Atri
*l'apprenant*

In response to

Responses

Browse pgsql-hackers by date

  From Date Subject
Next Message Vladimir Koković 2014-04-26 17:39:40 make check-world problem
Previous Message Tom Lane 2014-04-26 17:22:13 Re: includedir_internal headers are not self-contained