One of my repeat clients asked me if a query goes to parallel do they use all the threads. We can have parallelism and thread with no work.
SQL SERVER – Top 1 and Index Scan
Scans are not always bad they are there because they are needed. Let us see a very simple demonstration about Top 1 and Index Scan.
SQL SERVER – JOIN Elimination for Not Selected Column
The question is about JOIN Elimination for Not Selected Column. It was discussed in the Comprehensive Database Performance Health Check.
SQL SERVER – Logical Processing Order of the SELECT Statement
Why the result we get is the result we get. The answer is very simple – it is because of the Logical Processing Order of the SELECT Statement.
SQL SERVER – Distinct and ORDER BY
I have made note that ORDER BY is not required when DISTINCT is used. Let us understand the same subject in detail. Let us learn today.
SQL SERVER – TOP and DISTINCT – Epic Confusion – SQL in Sixty Seconds #141
DBAs from the client’s organization ended up an argument about how T-SQL works. The discussion was about the epic confusion about TOP and DISTINCT.
Performance Challenge – Write Efficient Query – SQL in Sixty Seconds #140
Recently while working with my client I ended up in a very interesting situation where my client wanted me to write an Efficient Query.