Re: [HACKERS] Re: [SQL] prob with aggregate and group by - returns multiplesh

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Don Baccus <dhogaza@pacifier.com>
Cc: Thomas Lockhart <lockhart@alumni.caltech.edu>, Bruce Momjian <pgman@candle.pha.pa.us>, "'pgsql-sql@postgresql.org'" <pgsql-sql@postgreSQL.org>, PostgreSQL Development <pgsql-hackers@postgreSQL.org>
Date: 2000-02-29T16:09:37Z
Lists: pgsql-hackers
Don Baccus <dhogaza@pacifier.com> writes:
> I vote for the SQL92 TEMPORARY.  Let's not add a keyword that is non-standard
> just because one or another commercial database makes use of it,

You're missing the point: we are not talking about *adding* a keyword,
we're talking about *removing* one that we've already supported for
a year or so.  That changes matters considerably, IMHO.

I have in fact been able to make a conflict-free grammar in which TEMP
is accepted but not reserved.  It requires a certain amount of
redundancy in the productions (see below), but I think this is a
worthwhile tradeoff for not breaking existing user code.

Shall I commit this?

			regards, tom lane


/*
 * Redundancy here is needed to avoid shift/reduce conflicts,
 * since TEMP is not a reserved word.  See also OptTemp.
 *
 * The result is a cons cell (not a true list!) containing
 * a boolean and a table name.
 */
OptTempTableName:  TEMPORARY opt_table relation_name
                { $$ = lcons(makeInteger(TRUE), (List *) $3); }
            | TEMP opt_table relation_name
                { $$ = lcons(makeInteger(TRUE), (List *) $3); }
            | LOCAL TEMPORARY opt_table relation_name
                { $$ = lcons(makeInteger(TRUE), (List *) $4); }
            | LOCAL TEMP opt_table relation_name
                { $$ = lcons(makeInteger(TRUE), (List *) $4); }
            | GLOBAL TEMPORARY opt_table relation_name
                {
                    elog(ERROR, "GLOBAL TEMPORARY TABLE is not currently supported");
                    $$ = lcons(makeInteger(TRUE), (List *) $4);
                }
            | GLOBAL TEMP opt_table relation_name
                {
                    elog(ERROR, "GLOBAL TEMPORARY TABLE is not currently supported");
                    $$ = lcons(makeInteger(TRUE), (List *) $4);
                }
            | TABLE relation_name
                { $$ = lcons(makeInteger(FALSE), (List *) $2); }
            | relation_name
                { $$ = lcons(makeInteger(FALSE), (List *) $1); }
        ;