What a Merge Join needs and when it is fast: two sorted inputs with matching column types. Presorted B-tree indexes make it quick, extra sorts make it costly.
SQL SERVER – Restrictions of Views – T SQL View Limitations
SQL Server views come with many rules, like ANSI_NULLS and QUOTED_IDENTIFIER being on. My list of view limitations, corrected with help from Ben Taylor.
SQL SERVER – Good, Better and Best Programming Techniques
My notes for a programmers meeting on Good, Better and Best Programming Techniques in SQL Server, plus a funny bug ticket about a client who got no email.
SQL SERVER – Query to Retrieve the Nth Maximum Value
Finding the nth Maximum Value means deciding how ties should count. Here, I rank distinct known salaries.
SQL SERVER – Locking Hints with Correct Scope and Safe Examples
Locking Hints change how a table reference participates in locking. I choose the required consistency before changing the query.
SQL SERVER – SELECT vs. SET Performance Comparison
SELECT vs. SET for local variables: SELECT can assign several at once and runs faster in a loop, while SET is the ANSI standard and assigns one at a time.
SQL SERVER – Difference Between Unique Index vs Unique Constraint
Unique Index vs Unique Constraint: is there a difference? No. A unique constraint creates a unique index, and performance is the same. Syntax for both.