Indexing

Disabling Clustered Indexes in SQL Server – a really good idea?

Last week I taught an internal SQL Server Performance Tuning course to a customer in Switzerland. As usual we had a lot of fun, and at some point an attendee asked me one of the best questions of my life: “Can you disable a Clustered Index?” At first I was really scared about that question, …

Disabling Clustered Indexes in SQL Server – a really good idea? + read more

Unique and non-unique non-clustered indexes on a non-unique clustered index

In the last weblog post I have talked about the differences in unique and non-unique non-clustered indexes on a unique clustered index. In this weblog post I want to talk about the differences of non-clustered indexes defined on a non-unique clustered index. As you already know from this posting, SQL Server handles non-unique clustered indexes …

Unique and non-unique non-clustered indexes on a non-unique clustered index + read more

Unique and non-unique non-clustered indexes on a unique clustered index

In the last weblog post I have talked about the difference of unique and non-unique clustered indexes. As you have seen SQL Server uses an internal overhead of 4 bytes (the so-called uniquifier) to make non-unique clustered index rows unique. Today I want to work out the difference between unique and non-unique non-clustered indexes defined …

Unique and non-unique non-clustered indexes on a unique clustered index + read more