Fix command completion for CREATE TABEL ... AS

(Please note that the patches:
"[PATCHES] Allow arbitrary levels of analyze/rewriting" and
"[PATCHES] Fix issuing of multiple command completions per command"
must be applied before this on)

This patch fixes the response for a CREATE TABLE ... AS statement.
Before you would see:

test=# create table b as select * from a;
SELECT

because it is internally transformed into the equivalent of

test=# select * into c from a;
SELECT

With this patch one now sees:

test=# create table b as select * from a;
CREATE

as expected.

ChangeLog:

* src/backend/tcop/pquery.c (ProcessQuery): Allow the caller to
specify the command tag. Create a tag based on commandType if
no
tag specified by caller.
* src/include/tcop/pquery.h: Adjust declaration for the above
function.
* src/backend/commands/explain.c (ExplainOneQuery): Adjust call
to
the above function.
* src/backend/tcop/postgres.c (pg_exec_query_string): Call
ProcessQuery() with the command tag that refers to the original
command, before rewriting.
(CreateCommandTag): Handle T_CreateAsStmt nodes.
* src/include/nodes/nodes.h: Add T_CreateAsStmt for CREATE
TABLE...AS.
* src/include/nodes/parsenodes.h: Add CreateAsStmt for CREATE
TABLE...AS.
* src/backend/nodes/copyfuncs.c (copyObject): Handle
T_CreateAsStmt.
* src/backend/nodes/equalfuncs.c (equal): Ditto.
* src/backend/parser/gram.y: Parse CREATE TABLE...AS into a
CreateAsStmt.
* src/backend/parser/analyze.c (transformStmt): Rewrite a
CreateAsStmt into a SelectStmt.

--
Fernando Nasser
Red Hat Canada Ltd. E-Mail: fnasser(at)redhat(dot)com
2323 Yonge Street, Suite #300
Toronto, Ontario M4P 2C9