I have a table where the data I really want is being stored in a text field (which I am getting use "Like"). However you can filter to a super-set of that data with a straight number comparison. If I have both filters in my where clause, do I have any control over the order in which the filters are applied. (IE: Have it filter to numbers then do the text search?)
asked Jan 15, 2010 at 03:24 PM in Default
It is the optimizers job to decide which is the fastest method to return the data. So no you dont get control directly , but you will influence the decisions it makes by using indexes etc.
answered Jan 15, 2010 at 03:33 PM
Actually you can force a specific execution plan in at least two ways:
But i do not recommend you to try to force SQL to ignore the "optimizer" unless you know you are much more intellegent than the developers of the SQL optimizer. It is easy to think that this execution plan is the best, but are you sure? What will happen when your data is changed? Maybe your number column is not selective enough and you force it to use that index? Then you end up with an execution plan that is outperformed of other possible execution plans that SQL optimizer wants to use.
for more information see:
answered Jan 18, 2010 at 06:38 AM