Showing posts with label set based. Show all posts
Showing posts with label set based. Show all posts

Tuesday, 12 March 2013

Remove a Cursor From a Stored Procedure - Part 2

Why is it so slow?!?!?
In my last post, I used a stored procedure from a database I manage to illustrate a real world example of converting a cursor into set based SQL. In this post I will look into a the mechanics behind the scenes and explain at least one of the reasons why it is generally unwise to use cursors when a set based query will provide the same results.

Thursday, 7 March 2013

Remove a Cursor From a Stored Procedure - Part 1

A huge problem DBAs encounter with system performance is the ever-present cursor. While there are some scenarios where cursors are unavoidable (or at least difficult to avoid), many instances are down to the developer being more comfortable writing cursors - or some myths as to why a cursor is better. That said, here is a short post highlighting some cursor pros or (non-cons): When are TSQL Cursors the best or only option?

In my organisation, and no doubt many others, the problem stems from the fact that the developers writing SQL are not SQL developers. Rather they are [insert relevant coding language] developers. And in many programming languages processing is best performed on a row-by-row basis. Not so SQL, especially T-SQL.