difference between transaction Isolation Level 1 & 2

[Manish Jaju]

What is difference between transaction Isolation Level 1 & 2 which is commited Read and Repeatable Read.... I am a bit confuse about that.

[Stan James]

We had much confusion on our team because EJB, DB2 and Oracle all use different words for the same thing and have different levels of support. Here's aUniversity Lecture that I found helpful.

Some of my notes:

Repeatable Read (RR) locks all the rows an application references within a unit of work.

Read Stability (RS) locks only those rows that an application retrieves within a unit of work

Cursor Stability (CS) locks any row accessed by a transaction of an application while the cursor is positioned on the row.

Uncommitted read does not lock other applications out of the row it is reading, unless the other application attempts to drop or alter the table

JDBC                DB2 
SERIALIZABLE     == Repeatable read 
REPEATABLE READ  == Read stability 
READ COMMITTED   == Cursor stability 
READ UNCOMMITTED == Uncommitted read 

IBM Documentation

Best of luck in this confusing area!

[Jessica Sant]

I'm going to move this to the JDBC forum seeing as though this is about various Database isolation levels.

So please post your replies there, thanks!