JOINS, EXISTS or IN which is better? Few questions on SQL

Question

I have few questions on SQL..

1. How to analyze the performance of a query? Any software, inbuilt features of MSSQL server 2005/2008?

2. What shou

Answer 1

1. Use the SQL Server Management Studio, and include Actual Execution Plan and SET STATISTICS TIME and SET STATISTICS IO.

2. This in corresponds to a JOIN, but rewriting probably won't matter. A guess could be that you need indexes on enquiry_courses.enquiry_id and on enquiries.session_id to improve query performance.