What is Cardinality, and how do you find it for a column? This simple script shows the percentage of unique values, using an AdventureWorks table.
SQL SERVER – How to Know Transaction Isolation Level for Each Session?
An outsourced app had teams using different coding standards, and performance suffered. Here is how to find the transaction isolation level of each session.
The Tipping Point: Why SQL Server Skips Your Nonclustered Index
Find the tipping point where key lookups cost more than a scan, then compare covering and filtered indexes with measured reads.
How to Force a Parallel Execution Plan for a Query? – Interview Question of the Week #170
A customer asked how to force a Parallel Execution Plan for a query. Here are two methods, including QUERYTRACEON 8649, with a simple example.
Faster Backups With BUFFERCOUNT and MAXTRANSFERSIZE, Measured
Measure faster backups by changing BUFFERCOUNT, MAXTRANSFERSIZE, and backup stripes one at a time while tracking speed and memory.
Which is Better for Performance – SELECT or SET? – Interview Question of the Week #166
Which is Better for Performance, SELECT or SET? In a loop, one SELECT that assigns several variables beats separate SET statements. Here is why.
Automatic Plan Correction: Reading SQL Server’s Tuning Advice
Read automatic plan correction advice, compare regressed and recommended plans, and verify that forcing the last good plan held.