Performance Killers in MSSQL

• Frequent recompilation of execution plans
• Inaccurate statistics
• Excessive use or improper configuration of tempdb
• Excessive blocking and deadlocks
• Excessive fragmentation
• Improper use of cursors
• Improper configuration of the database log
• Non-reusable execution plans
• Non-set-based operations, usually T-SQL cursors
• Poor database design
• Poor query design
• Poor indexing
• Poor execution plans, usually caused by parameter sniffing

Sp_rename fails : Either the parameter @objname is ambiguous or the claimed @objtype (object) is wrong

You can get below error if you have ‘DOT’ in between your constraint name. SP_rename fails because object_id(ContraintnamewithDOT) returns NULL for constraint objects with DOT (.) in their name.

Sp_rename fails with Msg 15248, Level 11, State 1, Procedure sp_rename, Line 357
Either the parameter @objname is ambiguous or the claimed @objtype (object) is wrong.

The solution to above problem is to drop and recreate the constraint without DOT