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HOT updates. When we update a tuple without changing any of its indexed
authorTom Lane <tgl@sss.pgh.pa.us>
Thu, 20 Sep 2007 17:56:33 +0000 (17:56 +0000)
committerTom Lane <tgl@sss.pgh.pa.us>
Thu, 20 Sep 2007 17:56:33 +0000 (17:56 +0000)
commit282d2a03dd30804b01f8042f640d638c2ee76604
tree004f08ce31f1bfb03ab55571ad7867babe5b3d7f
parentbbf4fdc2538097bb3103806e1419ceef1f289203
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.
65 files changed:
contrib/pgstattuple/pgstattuple.c
doc/src/sgml/catalogs.sgml
doc/src/sgml/monitoring.sgml
doc/src/sgml/ref/create_index.sgml
src/backend/access/gin/ginentrypage.c
src/backend/access/gin/ginvacuum.c
src/backend/access/gin/ginxlog.c
src/backend/access/gist/gist.c
src/backend/access/gist/gistutil.c
src/backend/access/gist/gistvacuum.c
src/backend/access/hash/hashinsert.c
src/backend/access/hash/hashovfl.c
src/backend/access/hash/hashpage.c
src/backend/access/heap/Makefile
src/backend/access/heap/README.HOT [new file with mode: 0644]
src/backend/access/heap/heapam.c
src/backend/access/heap/hio.c
src/backend/access/heap/pruneheap.c [new file with mode: 0644]
src/backend/access/heap/rewriteheap.c
src/backend/access/index/genam.c
src/backend/access/index/indexam.c
src/backend/access/nbtree/nbtinsert.c
src/backend/access/nbtree/nbtsort.c
src/backend/access/nbtree/nbtxlog.c
src/backend/catalog/index.c
src/backend/catalog/indexing.c
src/backend/catalog/system_views.sql
src/backend/catalog/toasting.c
src/backend/commands/indexcmds.c
src/backend/commands/sequence.c
src/backend/commands/vacuum.c
src/backend/commands/vacuumlazy.c
src/backend/executor/execMain.c
src/backend/executor/execUtils.c
src/backend/executor/nodeBitmapHeapscan.c
src/backend/executor/spi.c
src/backend/nodes/tidbitmap.c
src/backend/optimizer/plan/planner.c
src/backend/optimizer/util/plancat.c
src/backend/optimizer/util/var.c
src/backend/postmaster/pgstat.c
src/backend/storage/buffer/bufmgr.c
src/backend/storage/page/bufpage.c
src/backend/utils/adt/pgstatfuncs.c
src/backend/utils/cache/plancache.c
src/backend/utils/cache/relcache.c
src/include/access/heapam.h
src/include/access/htup.h
src/include/access/relscan.h
src/include/catalog/catversion.h
src/include/catalog/pg_attribute.h
src/include/catalog/pg_index.h
src/include/catalog/pg_proc.h
src/include/nodes/execnodes.h
src/include/nodes/plannodes.h
src/include/nodes/relation.h
src/include/optimizer/var.h
src/include/pgstat.h
src/include/storage/bufmgr.h
src/include/storage/bufpage.h
src/include/utils/plancache.h
src/include/utils/rel.h
src/include/utils/relcache.h
src/test/regress/expected/create_index.out
src/test/regress/expected/rules.out