Re: Polyphase merge is obsolete - Mailing list pgsql-hackers

From Peter Geoghegan
Subject Re: Polyphase merge is obsolete
Date
Msg-id CAH2-WzmJvFOZb+P=xAh2fK4tK2ad86r2A2q_rdq4QaXKAfwifw@mail.gmail.com
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In response to Re: Polyphase merge is obsolete  (John Naylor <john.naylor@enterprisedb.com>)
List pgsql-hackers
On Tue, Oct 5, 2021 at 10:25 AM John Naylor
<john.naylor@enterprisedb.com> wrote:
> int64 is used elsewhere in this file, and I see now reason to do otherwise.

Right. The point of using int64 in tuplesort.c is that the values may
become negative in certain edge-cases. The whole LACKMEM() concept
that tuplesort.c uses to enforce work_mem limits sometimes allows the
implementation to use slightly more memory than theoretically
allowable. That's how we get negative values.

-- 
Peter Geoghegan



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