Some SQL statements will be running very slow after SET ROWCOUNT or TOP is used. SET ROWCOUNT and TOP are used to tell SQL Server to select a specific number of rows from the SQL statements instead of extracting all records. Not many people know that SQL Server will try to re-optimize your SQL statements after you adding SET ROWCOUNT or TOP, the result is normally good after re-optimization of your SQL statements that can generate query plans for retrieving the first few records as faster...
How to Tune Bad Performance SET ROWCOUNT SQL Statements for SQL Server?
How to Tune Bad Performance SET ROWCOUNT SQL Statements for SQL Server?