> 1. "In the above case, since all transactions are started with IMMEDIATE,” -- > the diagram is actually using EXCLUSIVE transactions not IMMEDIATE > 2. "they behave as writers, and concurrent transactions are blocked" — this > implies to me that all transactions are blocked, and conflicts with the first > sentence which says (correctly) that a write lock allows concurrent readers
In the context of enforcing serial execution, it doesn’t matter if all transactions are started with `IMMEDIATE` or if all transactions are started with `EXCLUSIVE`. When using these behaviours, locks are acquired at the beginning of a transaction, and are retained till commit or abort. In `BEGIN IMMEDIATE` mode, all transactions try to acquire `RESERVED` locks at the beginning, meaning there are no readers. If one transaction succeeds, other concurrent transactions get blocked. Rahul _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
