pgsql: Add COST and ROWS options to CREATE/ALTER FUNCTION, plus

Log Message:
-----------
Add COST and ROWS options to CREATE/ALTER FUNCTION, plus underlying pg_proc
columns procost and prorows, to allow simple user adjustment of the estimated
cost of a function call, as well as control of the estimated number of rows
returned by a set-returning function. We might eventually wish to extend this
to allow function-specific estimation routines, but there seems to be
consensus that we should try a simple constant estimate first. In particular
this provides a relatively simple way to control the order in which different
WHERE clauses are applied in a plan node, which is a Good Thing in view of the
fact that the recent EquivalenceClass planner rewrite made that much less
predictable than before.

Modified Files:
--------------
pgsql/doc/src/sgml:
catalogs.sgml (r2.142 -> r2.143)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/catalogs.sgml.diff?r1=2.142&r2=2.143)
pgsql/doc/src/sgml/ref:
alter_function.sgml (r1.12 -> r1.13)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/alter_function.sgml.diff?r1=1.12&r2=1.13)
create_function.sgml (r1.70 -> r1.71)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/create_function.sgml.diff?r1=1.70&r2=1.71)
pgsql/src/backend/bootstrap:
bootstrap.c (r1.228 -> r1.229)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/bootstrap/bootstrap.c.diff?r1=1.228&r2=1.229)
pgsql/src/backend/catalog:
pg_aggregate.c (r1.84 -> r1.85)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/pg_aggregate.c.diff?r1=1.84&r2=1.85)
pg_proc.c (r1.142 -> r1.143)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/pg_proc.c.diff?r1=1.142&r2=1.143)
pgsql/src/backend/commands:
functioncmds.c (r1.81 -> r1.82)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/functioncmds.c.diff?r1=1.81&r2=1.82)
proclang.c (r1.70 -> r1.71)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/proclang.c.diff?r1=1.70&r2=1.71)
pgsql/src/backend/optimizer/path:
costsize.c (r1.175 -> r1.176)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/optimizer/path/costsize.c.diff?r1=1.175&r2=1.176)
pgsql/src/backend/optimizer/plan:
createplan.c (r1.222 -> r1.223)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/optimizer/plan/createplan.c.diff?r1=1.222&r2=1.223)
setrefs.c (r1.127 -> r1.128)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/optimizer/plan/setrefs.c.diff?r1=1.127&r2=1.128)
pgsql/src/backend/optimizer/util:
clauses.c (r1.230 -> r1.231)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/optimizer/util/clauses.c.diff?r1=1.230&r2=1.231)
pgsql/src/backend/parser:
gram.y (r2.574 -> r2.575)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/parser/gram.y.diff?r1=2.574&r2=2.575)
keywords.c (r1.181 -> r1.182)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/parser/keywords.c.diff?r1=1.181&r2=1.182)
pgsql/src/backend/utils:
Gen_fmgrtab.sh (r1.34 -> r1.35)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/Gen_fmgrtab.sh.diff?r1=1.34&r2=1.35)
pgsql/src/backend/utils/cache:
lsyscache.c (r1.145 -> r1.146)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/cache/lsyscache.c.diff?r1=1.145&r2=1.146)
pgsql/src/bin/pg_dump:
pg_dump.c (r1.456 -> r1.457)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/pg_dump.c.diff?r1=1.456&r2=1.457)
pgsql/src/include/catalog:
catversion.h (r1.375 -> r1.376)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/catversion.h.diff?r1=1.375&r2=1.376)
pg_attribute.h (r1.129 -> r1.130)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_attribute.h.diff?r1=1.129&r2=1.130)
pg_class.h (r1.99 -> r1.100)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_class.h.diff?r1=1.99&r2=1.100)
pg_proc.h (r1.439 -> r1.440)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_proc.h.diff?r1=1.439&r2=1.440)
pgsql/src/include/optimizer:
clauses.h (r1.85 -> r1.86)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/optimizer/clauses.h.diff?r1=1.85&r2=1.86)
cost.h (r1.83 -> r1.84)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/optimizer/cost.h.diff?r1=1.83&r2=1.84)
planmain.h (r1.98 -> r1.99)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/optimizer/planmain.h.diff?r1=1.98&r2=1.99)
pgsql/src/include/utils:
lsyscache.h (r1.114 -> r1.115)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/lsyscache.h.diff?r1=1.114&r2=1.115)
pgsql/src/test/regress/expected:
opr_sanity.out (r1.71 -> r1.72)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/opr_sanity.out.diff?r1=1.71&r2=1.72)
pgsql/src/test/regress/sql:
opr_sanity.sql (r1.57 -> r1.58)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/sql/opr_sanity.sql.diff?r1=1.57&r2=1.58)