pgsql: Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH.

Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH.

This patch implements data-modifying WITH queries according to the
semantics that the updates all happen with the same command counter value,
and in an unspecified order.  Therefore one WITH clause can't see the
effects of another, nor can the outer query see the effects other than
through the RETURNING values.  And attempts to do conflicting updates will
have unpredictable results.  We'll need to document all that.

This commit just fixes the code; documentation updates are waiting on
author.

Marko Tiikkaja and Hitoshi Harada

Branch
------
master

Details
-------
http://git.postgresql.org/pg/commitdiff/389af951552ff2209eae3e62fa147fef12329d4f

Modified Files
--------------
src/backend/commands/tablecmds.c        |    3 +-
src/backend/commands/view.c             |   14 +
src/backend/executor/execMain.c         |  155 ++++++---
src/backend/executor/execUtils.c        |    2 +
src/backend/executor/nodeModifyTable.c  |  151 ++++++---
src/backend/nodes/copyfuncs.c           |    4 +
src/backend/nodes/equalfuncs.c          |    1 +
src/backend/nodes/nodeFuncs.c           |   50 +++
src/backend/nodes/outfuncs.c            |    6 +-
src/backend/nodes/readfuncs.c           |    1 +
src/backend/optimizer/plan/createplan.c |    5 +-
src/backend/optimizer/plan/planner.c    |   22 +-
src/backend/optimizer/plan/setrefs.c    |   16 +-
src/backend/optimizer/plan/subselect.c  |   11 +-
src/backend/parser/analyze.c            |   16 +
src/backend/parser/gram.y               |    4 +-
src/backend/parser/parse_clause.c       |    2 +-
src/backend/parser/parse_cte.c          |   60 +++-
src/backend/parser/parse_relation.c     |   21 ++-
src/backend/parser/parse_target.c       |   10 +-
src/backend/rewrite/rewriteDefine.c     |    8 +
src/backend/rewrite/rewriteHandler.c    |   68 ++++
src/backend/tcop/pquery.c               |   36 ++-
src/backend/tcop/utility.c              |    2 +
src/backend/utils/adt/ruleutils.c       |    2 +-
src/backend/utils/cache/plancache.c     |    1 +
src/include/catalog/catversion.h        |    2 +-
src/include/executor/executor.h         |    2 +-
src/include/nodes/execnodes.h           |    9 +-
src/include/nodes/parsenodes.h          |   12 +-
src/include/nodes/plannodes.h           |    4 +
src/include/nodes/relation.h            |    4 +-
src/include/optimizer/planmain.h        |    4 +-
src/include/parser/parse_node.h         |    1 +
src/include/parser/parse_relation.h     |    2 +-
src/include/utils/portal.h              |    6 +
src/test/regress/expected/with.out      |  563 ++++++++++++++++++++++++++++++-
src/test/regress/sql/with.sql           |  204 +++++++++++-
38 files changed, 1323 insertions(+), 161 deletions(-)