pgsql: Tweak dynahash.c to avoid wasting memory space in non-shared hash - Mailing list pgsql-committers

From tgl@postgresql.org (Tom Lane)
Subject pgsql: Tweak dynahash.c to avoid wasting memory space in non-shared hash
Date
Msg-id 20060625182949.498859FA378@postgresql.org
Whole thread Raw
List pgsql-committers
Log Message:
-----------
Tweak dynahash.c to avoid wasting memory space in non-shared hash tables.
palloc() will normally round allocation requests up to the next power of 2,
so make dynahash choose allocation sizes that are as close to a power of 2
as possible.
Back-patch to 8.1 --- the problem exists further back, but a much larger
patch would be needed and it doesn't seem worth taking any risks.

Modified Files:
--------------
    pgsql/src/backend/utils/hash:
        dynahash.c (r1.67 -> r1.68)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/hash/dynahash.c.diff?r1=1.67&r2=1.68)
    pgsql/src/include/utils:
        hsearch.h (r1.42 -> r1.43)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/hsearch.h.diff?r1=1.42&r2=1.43)

pgsql-committers by date:

Previous
From: momjian@postgresql.org (Bruce Momjian)
Date:
Subject: pgsql: Add: < * Reuse index tuples that point to rows that are not
Next
From: tgl@postgresql.org (Tom Lane)
Date:
Subject: pgsql: Tweak dynahash.c to avoid wasting memory space in non-shared hash