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