Best practices for T-SQL querying

There are a number of best practices about writing good T-SQL that don't constitute a pattern or anti-pattern (this something we will discuss in upcoming chapters but that are important enough to observe when we want to write good queries. This section covers those practices.

Referencing objects

Always reference objects by their two-part name (<schema>.<name>) in T-SQL code because not doing so has some performance implications.

Using two-part object names avoids name resolution delays during query compilation: if the default schema for a user connecting to SQL Server is dbo, and that user attempts to execute the stored HumanResources.uspUpdateEmployeePersonalInfo procedure...