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.
Queries Using Specific Index – SQL in Sixty Seconds #180
The challenge I face is that often DBAs ask me to prove that indexes are really not used by queries. Let us learn about Queries Using Specific Index.
Find Queries Using an Index in the SQL Server Plan Cache
Find queries using an index by searching cached plans for its exact name. See the script, a surprise result, and what an unused index costs in SQL Server.
One Scan for 3 Count Sum – SQL in Sixty Seconds #178
Well, the answer is pretty straight forward and that is what we are going to see in today’s video of One Scan for 3 Count Sum.
SQL Server – Single Scan for 3 Operations – COUNT(*) COUNT(1) SUM(1)
Today we will take the same conversation to the next level by discussing Single Scan for 3 Operations – COUNT(*) COUNT(1) SUM(1).
COUNT(*) and Index Frequently Asked Questions
My Index Frequently Asked Questions discussion follows the counting video. I distinguish exact results, estimates and the expression being counted.
COUNT(*) and Index – SQL in Sixty Seconds #175
Earlier I wrote two blog post on the topic of COUNT(*) and Index and today I have to build a video on that topic as many of you really wanted.