Test index key order with equality, range, and OR predicates, then use seek predicates and logical reads to choose the lead column.
Does Sort Order in Index Column Matters for Performance? – Interview Question of the Week #199
Does the sort order in an index column matter for performance? Yes, in some specific scenarios, and here is an example from a recent Health Check question.
How to Find Size of the Index for Tables? – Interview Question of the Week #198
How do you find the size of the index for tables? A client asked me during a Health Check, and this script lists schema, table, index and size in KB and MB.
SQL SERVER – Parallelism for Heap Scan
Two DBAs asked me if their table needed a clustered index. Our conversation during a Health Check turned into a lesson on parallelism for Heap Scan.
SQL Authroity News – Optimizing Lazy Spool – PASS Blog
A sneak preview of my SQLPASS sessions: I wrote about optimizing Lazy Spool on the PASS blog, and here are the first two paragraphs with a link to the rest.
Do Index Reorganization Update Statistics? – Interview Question of the Week #196
Question: Do Index Reorganization Update Statistics?
Answer: No. Index Reorganization does not update Statistics of your database.
How to Find Queries Using an Index From SQL Server Plan Cache? – Interview Question of the Week #195
Before I dropped an unused index, my client’s CEO wanted proof. Here is how to find queries using an index from the SQL Server plan cache.