To index a computed column, define the formula once on the table and create a normal index on it. This post loads 200,000 rows, shows the scan, then the seek after the index, and tests the rules that decide whether SQL Server accepts the column.
SQL SERVER – High Frequency Cached Query Counts and Statement Metrics
I measure High Frequency cached statements with decimal executions-per-second arithmetic. A customer wanted to identify the busiest queries.
SQL SERVER – Stored Procedure Timing and Cached Measurements
SET STATISTICS TIME reports CPU and elapsed execution time for Stored Procedures. A customer wanted to measure a run without adding statements manually.
SQL SERVER – Using NOEXPAND with Indexed View
NOEXPAND treats an indexed view as stored indexed data instead of expanding its base tables. Customer results have differed.
SQL SERVER – Parameter Sniffing and Bad Plan
Disabling parameter sniffing does not guarantee that a bad plan becomes good. That remains my answer to the customer question.
Parallelism in Express Edition: What the Limits Mean
Parallelism in Express Edition has its own reason code in the execution plan. This post reads that reason, shows the settings that keep a plan serial on any edition, and tests the check on a demo table.
SQL SERVER – Dirty Pages Clean Pages and the Correct Cache Commands
Clean Pages have no outstanding data-file write, while dirty pages contain unwritten changes. A customer asked which state was better.