pgsql: HOT updates. - Mailing list pgsql-committers

Log Message:
-----------
HOT updates.  When we update a tuple without changing any of its indexed
columns, and the new version can be stored on the same heap page, we no longer
generate extra index entries for the new version.  Instead, index searches
follow the HOT-chain links to ensure they find the correct tuple version.

In addition, this patch introduces the ability to "prune" dead tuples on a
per-page basis, without having to do a complete VACUUM pass to recover space.
VACUUM is still needed to clean up dead index entries, however.

Pavan Deolasee, with help from a bunch of other people.

Modified Files:
--------------
    pgsql/contrib/pgstattuple:
        pgstattuple.c (r1.29 -> r1.30)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/pgstattuple/pgstattuple.c?r1=1.29&r2=1.30)
    pgsql/doc/src/sgml:
        catalogs.sgml (r2.157 -> r2.158)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/catalogs.sgml?r1=2.157&r2=2.158)
        monitoring.sgml (r1.51 -> r1.52)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/monitoring.sgml?r1=1.51&r2=1.52)
    pgsql/doc/src/sgml/ref:
        create_index.sgml (r1.64 -> r1.65)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/create_index.sgml?r1=1.64&r2=1.65)
    pgsql/src/backend/access/gin:
        ginentrypage.c (r1.8 -> r1.9)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/gin/ginentrypage.c?r1=1.8&r2=1.9)
        ginvacuum.c (r1.16 -> r1.17)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/gin/ginvacuum.c?r1=1.16&r2=1.17)
        ginxlog.c (r1.8 -> r1.9)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/gin/ginxlog.c?r1=1.8&r2=1.9)
    pgsql/src/backend/access/gist:
        gist.c (r1.146 -> r1.147)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/gist/gist.c?r1=1.146&r2=1.147)
        gistutil.c (r1.23 -> r1.24)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/gist/gistutil.c?r1=1.23&r2=1.24)
        gistvacuum.c (r1.31 -> r1.32)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/gist/gistvacuum.c?r1=1.31&r2=1.32)
    pgsql/src/backend/access/hash:
        hashinsert.c (r1.46 -> r1.47)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/hash/hashinsert.c?r1=1.46&r2=1.47)
        hashovfl.c (r1.59 -> r1.60)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/hash/hashovfl.c?r1=1.59&r2=1.60)
        hashpage.c (r1.69 -> r1.70)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/hash/hashpage.c?r1=1.69&r2=1.70)
    pgsql/src/backend/access/heap:
        Makefile (r1.16 -> r1.17)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/heap/Makefile?r1=1.16&r2=1.17)
        heapam.c (r1.240 -> r1.241)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/heap/heapam.c?r1=1.240&r2=1.241)
        hio.c (r1.66 -> r1.67)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/heap/hio.c?r1=1.66&r2=1.67)
        rewriteheap.c (r1.6 -> r1.7)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/heap/rewriteheap.c?r1=1.6&r2=1.7)
    pgsql/src/backend/access/index:
        genam.c (r1.62 -> r1.63)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/index/genam.c?r1=1.62&r2=1.63)
        indexam.c (r1.98 -> r1.99)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/index/indexam.c?r1=1.98&r2=1.99)
    pgsql/src/backend/access/nbtree:
        nbtinsert.c (r1.159 -> r1.160)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/nbtree/nbtinsert.c?r1=1.159&r2=1.160)
        nbtsort.c (r1.112 -> r1.113)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/nbtree/nbtsort.c?r1=1.112&r2=1.113)
        nbtxlog.c (r1.45 -> r1.46)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/nbtree/nbtxlog.c?r1=1.45&r2=1.46)
    pgsql/src/backend/catalog:
        index.c (r1.284 -> r1.285)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/index.c?r1=1.284&r2=1.285)
        indexing.c (r1.114 -> r1.115)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/indexing.c?r1=1.114&r2=1.115)
        system_views.sql (r1.44 -> r1.45)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/system_views.sql?r1=1.44&r2=1.45)
        toasting.c (r1.7 -> r1.8)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/toasting.c?r1=1.7&r2=1.8)
    pgsql/src/backend/commands:
        indexcmds.c (r1.165 -> r1.166)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/indexcmds.c?r1=1.165&r2=1.166)
        sequence.c (r1.145 -> r1.146)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/sequence.c?r1=1.145&r2=1.146)
        vacuum.c (r1.358 -> r1.359)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/vacuum.c?r1=1.358&r2=1.359)
        vacuumlazy.c (r1.96 -> r1.97)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/vacuumlazy.c?r1=1.96&r2=1.97)
    pgsql/src/backend/executor:
        execMain.c (r1.297 -> r1.298)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/execMain.c?r1=1.297&r2=1.298)
        execUtils.c (r1.150 -> r1.151)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/execUtils.c?r1=1.150&r2=1.151)
        nodeBitmapHeapscan.c (r1.19 -> r1.20)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/nodeBitmapHeapscan.c?r1=1.19&r2=1.20)
        spi.c (r1.180 -> r1.181)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/spi.c?r1=1.180&r2=1.181)
    pgsql/src/backend/nodes:
        tidbitmap.c (r1.12 -> r1.13)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/nodes/tidbitmap.c?r1=1.12&r2=1.13)
    pgsql/src/backend/optimizer/plan:
        planner.c (r1.221 -> r1.222)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/optimizer/plan/planner.c?r1=1.221&r2=1.222)
    pgsql/src/backend/optimizer/util:
        plancat.c (r1.136 -> r1.137)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/optimizer/util/plancat.c?r1=1.136&r2=1.137)
        var.c (r1.70 -> r1.71)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/optimizer/util/var.c?r1=1.70&r2=1.71)
    pgsql/src/backend/postmaster:
        pgstat.c (r1.163 -> r1.164)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/postmaster/pgstat.c?r1=1.163&r2=1.164)
    pgsql/src/backend/storage/buffer:
        bufmgr.c (r1.223 -> r1.224)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/buffer/bufmgr.c?r1=1.223&r2=1.224)
    pgsql/src/backend/storage/page:
        bufpage.c (r1.73 -> r1.74)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/page/bufpage.c?r1=1.73&r2=1.74)
    pgsql/src/backend/utils/adt:
        pgstatfuncs.c (r1.44 -> r1.45)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/pgstatfuncs.c?r1=1.44&r2=1.45)
    pgsql/src/backend/utils/cache:
        plancache.c (r1.10 -> r1.11)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/cache/plancache.c?r1=1.10&r2=1.11)
        relcache.c (r1.262 -> r1.263)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/cache/relcache.c?r1=1.262&r2=1.263)
    pgsql/src/include/access:
        heapam.h (r1.126 -> r1.127)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/access/heapam.h?r1=1.126&r2=1.127)
        htup.h (r1.93 -> r1.94)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/access/htup.h?r1=1.93&r2=1.94)
        relscan.h (r1.56 -> r1.57)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/access/relscan.h?r1=1.56&r2=1.57)
    pgsql/src/include/catalog:
        catversion.h (r1.425 -> r1.426)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/catversion.h?r1=1.425&r2=1.426)
        pg_attribute.h (r1.132 -> r1.133)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_attribute.h?r1=1.132&r2=1.133)
        pg_index.h (r1.43 -> r1.44)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_index.h?r1=1.43&r2=1.44)
        pg_proc.h (r1.470 -> r1.471)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_proc.h?r1=1.470&r2=1.471)
    pgsql/src/include/nodes:
        execnodes.h (r1.177 -> r1.178)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/nodes/execnodes.h?r1=1.177&r2=1.178)
        plannodes.h (r1.94 -> r1.95)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/nodes/plannodes.h?r1=1.94&r2=1.95)
        relation.h (r1.145 -> r1.146)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/nodes/relation.h?r1=1.145&r2=1.146)
    pgsql/src/include/optimizer:
        var.h (r1.35 -> r1.36)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/optimizer/var.h?r1=1.35&r2=1.36)
    pgsql/src/include:
        pgstat.h (r1.65 -> r1.66)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/pgstat.h?r1=1.65&r2=1.66)
    pgsql/src/include/storage:
        bufmgr.h (r1.106 -> r1.107)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/storage/bufmgr.h?r1=1.106&r2=1.107)
        bufpage.h (r1.73 -> r1.74)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/storage/bufpage.h?r1=1.73&r2=1.74)
    pgsql/src/include/utils:
        plancache.h (r1.7 -> r1.8)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/plancache.h?r1=1.7&r2=1.8)
        rel.h (r1.101 -> r1.102)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/rel.h?r1=1.101&r2=1.102)
        relcache.h (r1.59 -> r1.60)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/relcache.h?r1=1.59&r2=1.60)
    pgsql/src/test/regress/expected:
        create_index.out (r1.25 -> r1.26)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/create_index.out?r1=1.25&r2=1.26)
        rules.out (r1.133 -> r1.134)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/rules.out?r1=1.133&r2=1.134)

Added Files:
-----------
    pgsql/src/backend/access/heap:
        README.HOT (r1.1)

(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/heap/README.HOT?rev=1.1&content-type=text/x-cvsweb-markup)
        pruneheap.c (r1.1)

(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/heap/pruneheap.c?rev=1.1&content-type=text/x-cvsweb-markup)