Thread: pgsql: Avoid running build_index_pathkeys() in situations where there

Log Message:
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Avoid running build_index_pathkeys() in situations where there cannot
possibly be any useful pathkeys --- to wit, queries with neither any
join clauses nor any ORDER BY request.  It's nearly free to check for
this case and it saves a useful fraction of the planning time for simple
queries.

Modified Files:
--------------
    pgsql/src/backend/optimizer/path:
        indxpath.c (r1.219 -> r1.220)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/optimizer/path/indxpath.c.diff?r1=1.219&r2=1.220)
        pathkeys.c (r1.83 -> r1.84)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/optimizer/path/pathkeys.c.diff?r1=1.83&r2=1.84)
    pgsql/src/include/optimizer:
        paths.h (r1.96 -> r1.97)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/optimizer/paths.h.diff?r1=1.96&r2=1.97)