On Tue, 2003-03-04 at 19:14, Tom Lane wrote: > Rod Taylor <[EMAIL PROTECTED]> writes: > > Might get somewhere by making a special domain thats marked as being > > serial, and using that in the column. > > I recall some discussion last year about making serial et al. into > domains over int4 and int8, rather than their current utter-hack > implementation. Can't recall if we found a problem with the idea, > or no one got around to doing it, or it just didn't seem to clean > things up enough to be worth the trouble. (AFAICS you'd still need > special-case code to set up the appropriate default expression for > each column; the domain constraint mechanism wouldn't handle that > for you.)
Slightly different thought. I had actually submitted a patch for the
above, but would have to dig through the archives to determine what the
problem was.
CREATE TABLE tab (column SERIAL);
Generates:
table(column serial_table_column)
domain serial_table_column
as int4 default nextval("serial_table_column")
Sequence serial_table_column.
Now, rather than having knowedge of the contents of nextval, we simply
trace the dependencies of the column through the domain to the sequence
-- since these will be known to exist.
Thus the below command could function fairly easily on serials:
ALTER SEQUENCE ON table(column)
The alternative is to simply implement the proposed 200N sequence
generator spec, which includes 'NEXT VALUE FOR <sequence>'.
With that in place, our default would then depend on the sequence, and
the ALTER SEQUENCE ON table(column) would function.
--
Rod Taylor <[EMAIL PROTECTED]>
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