How to create fast database queries

Archive for April 27th, 2009

Descending indexes

with 2 comments

From Stack Overflow:

When you create an index on a column or number of columns in MS SQL Server (I'm using version 2005), you can specify that the index on each column be either ascending or descending.

I'm having a hard time understanding why this choice is even here. Using binary sort techniques, wouldn't a lookup be just as fast either way?

What difference does it make which order I choose?

This matters when the composite indexes are used.

Let's create a sample table:
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Written by Quassnoi

April 27th, 2009 at 11:00 pm

Posted in SQL Server