SQL Server Plans : difference between Index Scan / Index Seek

Question

In a SQL Server Execution plan what is the difference between an Index Scan and an Index Seek

I\'m on SQL Server 2005.

Answer 1

An Index Scan happens when the index definition cannot find on a single row to satisfy search predicates. In this case SQL Server has to scan multiple pages to find a range of rows which satisfy the search predicates.

In the case of a Index Seek, SQL Server finds a single row matching search predicates using index definition.

Index Seeks are better and more effective.