Thread: pgsql/src/backend/utils/adt pg_lzcompress.c

pgsql/src/backend/utils/adt pg_lzcompress.c

From
tgl@postgresql.org
Date:
CVSROOT:    /cvsroot
Module name:    pgsql
Changes by:    tgl@postgresql.org    01/11/17 01:09:30

Modified files:
    src/backend/utils/adt: pg_lzcompress.c

Log message:
    Fix performance problems in TOAST compressor.  The management of
    search lists was broken in such a way that only the most recent
    instance of a given hash code would ever be searched, thus possibly
    missing longer matches further back.  Fixing this gave 5 to 10%
    compression improvement on some text test cases.  Additional small
    tweaks to improve speed of inner loops a little bit.  There is no
    compatibility issue created by this change, since the compressed data
    format and decompression algorithm don't change.