Hints (Transact-SQL)
Applies to: 
SQL Server
Azure SQL Database
Azure SQL Managed Instance
Hints are options or strategies specified for enforcement by the SQL Server query processor on SELECT, INSERT, UPDATE, or DELETE statements. The hints override any execution plan the query optimizer might select for a query.
Caution
Because the SQL Server query optimizer typically selects the best execution plan for a query, we recommend that <join_hint>, <query_hint>, and <table_hint> be used only as a last resort by experienced developers and database administrators.
The following hints are described in this section: