pgsql-server/ oc/src/sgml/release.sgml rc/back ...

CVSROOT:    /cvsroot
Module name:    pgsql-server
Changes by:    tgl@postgresql.org    03/01/20 13:55:08

Modified files:
    doc/src/sgml   : release.sgml
    src/backend/executor: nodeHashjoin.c nodeMergejoin.c
                          nodeNestloop.c
    src/backend/nodes: copyfuncs.c equalfuncs.c list.c outfuncs.c
    src/backend/optimizer: README
    src/backend/optimizer/geqo: geqo_eval.c geqo_main.c
    src/backend/optimizer/path: allpaths.c costsize.c indxpath.c
                                joinpath.c joinrels.c
    src/backend/optimizer/plan: createplan.c initsplan.c planmain.c
                                planner.c setrefs.c subselect.c
    src/backend/optimizer/prep: Makefile prepunion.c
    src/backend/optimizer/util: clauses.c joininfo.c pathnode.c
                                relnode.c tlist.c var.c
    src/backend/rewrite: rewriteManip.c
    src/backend/utils/adt: selfuncs.c
    src/include/nodes: nodes.h parsenodes.h pg_list.h relation.h
    src/include/optimizer: joininfo.h pathnode.h planmain.h
                           planner.h prep.h subselect.h tlist.h
                           var.h
    src/include/utils: selfuncs.h
    src/test/regress/expected: subselect.out
Added files:
    src/backend/optimizer/prep: prepjointree.c

Log message:
    IN clauses appearing at top level of WHERE can now be handled as joins.
    There are two implementation techniques: the executor understands a new
    JOIN_IN jointype, which emits at most one matching row per left-hand row,
    or the result of the IN's sub-select can be fed through a DISTINCT filter
    and then joined as an ordinary relation.
    Along the way, some minor code cleanup in the optimizer; notably, break
    out most of the jointree-rearrangement preprocessing in planner.c and
    put it in a new file prep/prepjointree.c.