Exploring SQL Server Query Optimization

Are you ready to dive into the fascinating world of SQL Server query optimization? Let's talk about the RID Lookup Operator, a key player in the SQL Server execution plan!  The RID Lookup Operator comes into play when we query a table that doesn't have a clustered index, unlike the commonly used primary key. Instead, SQL Server uses the Row ID (RID) to uniquely identify rows in such tables. Here's the deal: RID Lookup can be a performance challenge. Each RID Lookup operation translates into a separate I/O operation, which can slow down your query execution. So, it's essential to keep an eye on it, especially in larger datasets. Let us first create the below table and fill it with 3K records to use it in the below examples . The table can be created and filled with data using the T-SQL script below: CREATE TABLE   EmployeeData ( ID INT IDENTITY(1, 1) , EmployeeFirstName VARCHAR(50) , EmployeeLastName VARCHAR(50) , EmployeeAddress VARCHAR(MA...