Allow create_index_paths() to consider multiple join bitmapscan paths. In the initial cut at the "parameterized paths" feature, I'd simplified create_index_paths() to the point where it would only generate a single parameterized bitmap path per relation. Experimentation with an example supplied by Josh Berkus convinces me that that's not good enough: we really need to consider a bitmap path for each possible outer relation. Otherwise we have regressions relative to pre-9.2 versions, in which the planner picks a plain indexscan where it should have used a bitmap scan in queries involving three or more tables. Indeed, after fixing this, several queries in the regression tests show improved plans as a result of using bitmap not plain indexscans.
Branch ------ REL9_2_STABLE Details ------- http://git.postgresql.org/pg/commitdiff/26893906896d25b0119c57c90474c153bb8083c9 Modified Files -------------- src/backend/optimizer/path/indxpath.c | 98 +++++++++++++++++++++++++++----- src/test/regress/expected/join.out | 28 ++++++---- 2 files changed, 99 insertions(+), 27 deletions(-) -- Sent via pgsql-committers mailing list ([email protected]) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-committers
