Marc Herbert <[EMAIL PROTECTED]> writes:

>>> So before inserting a new record, it reads the max id
>>> value in the table and increases it by one for the new id. After
>>> insertion opertaion, TPCW commits transaction. MySQL server works
>>> correctly with the operation.

> You need a full SERIALIZABLE isolation level for this to be
> thread-safe since a predicate read is involved.


I just tested this manually with MySQL/InnoDB 5.0.24, using two
concurrent "select max(id)" transactions, and it's not
thread-safe. Both transactions happily insert the same n+1 value in
the table.

So it seems this InnoDB version does not really implement a
"serializable" level. Could you please do the same manual test with
your install? Thanks in advance.







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