Repeatable_Read_and_Serializable_isolation_level

Bruce's lecture on MVCC: In 9.1, we have repeatable read. This is old "Serializable". Now serializable adds another condition. When a conflict is detected, the transaction will be aborted. This will be covered by Friday's lecture on "Serializable Snapshot Isolation". I need to listen to it to have better idea how to support new isolation level.

SERIALIZABLE overview

• 'SERIALIZABLE' in 9.0 or older will be 'REPEATABLE READ' in 9.1 or later.
• 'SERIALIZABLE' tests footprint of each transaction and determine if it violates r-w and r-w conflict.
• This is implemented by list of read objects (rows, pages, or table --- escalates).

Important point is they completely work locally, even in distributed transactions, and you will notice that this does not require any change to XC --- GREAT!!