Cursor for updating in oracle dating in cochin usa
Read committed does not give you consistent results.
They are: Isolation Level Dirty Read Non-Repeatable Read Phantom Read Read Uncommitted Permitted Permitted Permitted Read Committed Permitted Permitted Repeatable Read Permitted Serializable Oracle supports explicitly two of the above isolation levels as they are defined ? Repeatable read is the isolation level they claim you must be at to get a read consistent result from a query.
It may have disappeared, it may have been updated, and so on. This means that if you executed a query at time T1, and re-execute it at time T2, additional rows may have been added to the database, which affects your results.
This differs from the non-repeatable read in that in this case, data you already read has not been changed but rather that more data satisfies your query criteria than before.
The result is that both tables contain a row with the value zero in them.
My question is that wouldn't the result be the same even if the isolation_level is not serializable? The text in BOLD is what the example is trying to demonstrate.