Igor Tandetnik wrote: > On 7/2/2014 3:04 AM, Clemens Ladisch wrote: >>> If all else fails, one could try and simulate BEGIN IMMEDIATE by running >>> a dummy modifying statement right after BEGIN - e.g. >>> >>> delete from table1 where 0; >> >> Would this be atomic? > > It would be part of the same transaction, wouldn't it?
In shared-cache mode, accesses from all threads are part of the same transaction (as far as the database file is concerned). SQL transactions are implemented on top of that. > However, I have no reason to believe, other than your word, that BEGIN > IMMEDIATE would not just work in this case. What makes you think it > wouldn't? In shared-cache mode, | a transaction is implicitly a read-transaction until it first writes | to a database table, at which point it becomes a write-transaction. (http://www.sqlite.org/sharedcache.html) There is no documented way to start a transaction with a write lock, thus I see no mechanism that could reliably prevent deadlocks. Regards, Clemens _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
