Wednesday, February 11, 2009

Transaction Isolation Levels

I was trying to think of an easy way to memorise/understand these.  What do others think of this approach?
Transaction Isolation Level Lost Update Dirty Read Non-Repeatable Read Phantom Reads Shared Locks Schema Stability Lock Alternate Reality Update Conflicts
Read committed N N Y Y Acquired for read, released immediately   N  
Read uncommitted N Y Y Y Not acquired for read Acquired N  
Repeatable read N N N Y Acquired for read, held for duration   N  
Serializable N N N N Locks range or entire table   N  
Snapshot N N N N Not acquired for read   Y Y
Read committed snapshot N N Y Y Not acquired for read   Y N
MCITP Self-Paced Training Kit (Exam 70-442): Designing and Optimizing Data Access by Using Microsoft  SQL Server(TM) 2005 (Self-Paced Training Kits)

1 comment:

  1. Comment by Kirk Jackson, on 11-FEB-2009 23:18 ( IP: , user id: )

    Very nice. Thanks,