pgsql-server/src backend/nodes/list.c backend/ ...

CVSROOT:    /cvsroot
Module name:    pgsql-server
Changes by:    tgl@postgresql.org    03/01/23 22:58:44

Modified files:
    src/backend/nodes: list.c
    src/backend/optimizer/path: indxpath.c pathkeys.c
    src/backend/optimizer/plan: initsplan.c
    src/backend/optimizer/util: joininfo.c relnode.c restrictinfo.c
    src/backend/utils/adt: selfuncs.c
    src/include/nodes: pg_list.h
    src/include/optimizer: joininfo.h paths.h planmain.h

Log message:
    Modify planner's implied-equality-deduction code so that when a set
    of known-equal expressions includes any constant expressions (including
    Params from outer queries), we actively suppress any 'var = var'
    clauses that are or could be deduced from the set, generating only the
    deducible 'var = const' clauses instead.  The idea here is to push down
    the restrictions implied by the equality set to base relations whenever
    possible.  Once we have applied the 'var = const' clauses, the 'var = var'
    clauses are redundant, and should be suppressed both to save work at
    execution and to avoid double-counting restrictivity.