Re: Horribly slow hash join - Mailing list pgsql-performance

From Tom Lane
Subject Re: Horribly slow hash join
Date
Msg-id 19681.1082302750@sss.pgh.pa.us
Whole thread Raw
In response to Re: Horribly slow hash join  (Dennis Bjorklund <db@zigo.dhs.org>)
Responses Re: Horribly slow hash join
List pgsql-performance
Dennis Bjorklund <db@zigo.dhs.org> writes:
> On Sat, 17 Apr 2004, Tom Lane wrote:
>> *some* set of inputs.  (Also, I have been harboring some notions of
>> supporting cross-type hash joins for integer types, which will not work
>> unless small int8 values hash the same as int4 etc.)

> The simple solution would be to always extend integers to 64 bits (or
> whatever the biggest integer is) before calculating the hash.

That creates portability issues though.  We do not depend on there being
a 64-bit-int type for anything except int8 itself, and I don't want to
start doing so.

            regards, tom lane

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