DETERMINISTIC as synonym for IMMUTABLE

Hello,

While reviewing PostgreSQL 8's SQL:2003 conformance (see the documentation
mailing list), I've come across a - possibly - easy-to-implement
conformance improvement for CREATE FUNCTION:

SQL:2003 uses the word DETERMINISTIC where PostgreSQL uses IMMUTABLE.
And SQL:2003 uses "NOT DETERMINISTIC" where PostgreSQL uses STABLE
or VOLATILE.

I suggest that DETERMINISTIC be added as a synonym for IMMUTABLE and that
"NOT DETERMINISTIC" be added as an alias for VOLATILE in PostgreSQL's
grammar for CREATE FUNCTION.

I might try creating a patch, but I'd rather spend my time finishing the
conformance review.

--
Greetings from Troels Arvin, Copenhagen, Denmark