> WAL does this already. You just need to BEGIN a transaction when you want it to BEGIN and COMMIT or ROLLBACK when you are done with it.
I was under the apparently mistaken impression that starting any transaction would block writes, even in WAL mode. Just to be clear, this would work: On multiple concurrent reader threads/connections: BEGIN; SELECT col FROM table; SELECT col FROM table; ROLLBACK; On a single concurrent writer thread/connection: BEGIN EXCLUSIVE; UPDATE table SET col = z; COMMIT; In a WAL database, none of the threads will block (the BEGIN EXCLUSIVE will not block the readers, and vice-versa), and the two SELECT's will always get the same value?
