Nvl versus Coalesce, and the winner is…

Most Oracle developers I know use NVL, rather than COALESCE for returning the first not null value of two arguments.  Most will cite it’s for habitual, historic reasons (COALESCE was introduced later in Oracle’s history) or because it’s shorter to type.

Well NVL and COALESCE do the same thing anyway, so why would I change?

Well, there’s one very good reason why you should the SQL standards function COALESCE over Oracle’s proprietary NVL….
Continue reading


CLOB Concatenation

Adding string data to a CLOB in Oracle can be a tad slow, when compared to other string concatenation situations.  I first became aware of this concatenation performance issue from my own coding experience, but also from threads on Oracle Technical Network and a blog post by Jonathan Lewis.

Continue reading