Re: Sequences without blank holes

MaRcElO PeReIrA writes:

> How can I assure a ''sequence WITHOUT holes''?

> $ SELECT max(prod_id)+1 FROM products;

You can do that, but

SELECT prod_id FROM products ORDER BY prod_id DESC LIMIT 1;

will be faster.  In fact, if you have a B-tree index on prod_id (which you
should), it will be nearly constant time.

Also, make sure if you do a SELECT, then some client application logic,
then an UPDATE, to do it in one transaction and use the appropriate
isolation level, locking, etc.

--
Peter Eisentraut   peter_e@gmx.net