Sequence functions

We need to track sequence usage in things like defaults. nextval()
function calls don't easily allow this to happen.

The 200N spec has NEXT VALUE FOR <seqname> as the equivalent to
nextval(), which would allow this to happen.

I can make VALUE an IDENT in gram.y to prevent it from becoming a
reserved keyword.

I would also like to add CURRENT VALUE FOR <seqname> for an equivalent
to currval(). CURRENT would need to become a reserved word for this to
happen.

The SQL spec has several reason why CURRENT should be reserved including
several cursor manipulation items (WHERE CURRENT OF), a windowing
function (is this based on cursors?), DISCONNECT, etc.

Any objections to making CURRENT a reserved word?

BTW, VALUE also seems to be used for a special form of unique
constraint. UNIQUE(VALUE) which is equivalent to UNIQUE(SELECT * FROM
<table>).

--
Rod Taylor <rbt(at)rbt(dot)ca>

PGP Key: http://www.rbt.ca/rbtpub.asc