As part of optimizing your SQL queries, if you want to line of code to include the execution plan, drag this instruction before execution.
SET STATISTICS SHOWPLAN_XML ON
If you want to optimize the recovery of your data in an environment with a default isolation level of Read Committed or SERIALIZBLE, slide this instruction before execution.
SET TRANSACTION ISOLATION LEVEL SNAPSHOT
As part of query optimization, you can associate a clean SQL query execution plan for you so to override the behavior of the query optimizer, see reference Plan in SQL Server Management Studio, you can create your SEEK FORCE clauses on your favorite index etc.
You can sometimes just be an update statistics 🙂
For the database novice, the positioning of the index is very important and is based on real data collecting tools (Production Environment)
As for the SQL Server after try: Database Engine Tuning Advisor, included in SSMS since the 2012 version.