Hello, some questions please about transactions/locks in a multithreaded environment, multiple applications, WAL mode, NO shared cache, NO read_uncommitted pragma:
???????????? Some examples: 1- UPDATE Internally, is the same thing that: BEGIN DEFERRED - UPDATE -COMMIT? 2- SELECT UPDATE In this example, the set of these commands is serialized? The two commands act on the same snapshot? So, two commands have the same data (same snapshot), but those data may be modified by another thread/process between SELECT and UPDATE, and UPDATE will be unaware of this previous change? 3- BEGIN (or BEGIN DIFFERED) SELECT UPDATE COMMIT Same as 2? 5- BEGIN IMMEDIATE SELECT UPDATE COMMIT I'm sure that the data can not be modified (between BEGIN IMMEDIATE and COMMIT) by another thread/proces? Thank you! olivier
