Performance Tuning

What are Locks?

What is a Lock? What is the process that transactions use to lock records to provide transaction isolation.


Transaction Isolation Levels

Transaction Isolation Levels are used to control data access concurrency. Concurrency controls can be Pessimistic or Optimistic.


Concurrency: Phantom Reads

A closer look at the Serializable Transaction Isolation Level and how it could prevent Phantom Reads concurrency issues in SQL Server.



Concurrency: Lost Updates

A closer look at the Read Committed Transaction Isolation Level and how it could allow Lost Update concurrency issues in SQL Server.


Concurrency: Dirty Reads

A closer look at the Read Uncommitted Transaction Isolation Level and how it could allow Dirty Reads in SQL Server.