Hi, all, some months ago i was tasked with writing a WWW/PHP/MySQL-based application which takes a group of meeting tables and randomly assigns them to participants (yes, this was/is a real application). One of the problems i faced is an inherent race condition in the selection of meeting slots. MySQL offers table locking, but it's riddled with bugs and doesn't work properly when subselects or aliases come into play (it fails loudly with cryptic/downright wrong messages). So i gave up on the idea of protecting against the race and just hoped for the best (so far, so good - it's a low-use app and the result of a race collision is not worth the development efforts needed to avoid it).
About 2 minutes ago i had the idea that i could open up an sqlite3 connection which is _only_ used as a mutex to block of access to the MySQL tables while those bits are running. (i tried doing something similar with MySQL back then, but MySQL's explicit table locking support is surprisingly limited and i couldn't get it working.) My question now is (assuming this is feasible): what SQL do i need to do this? Would it suffice to call BEGIN EXCLUSIVE on an empty db, and only continue on to the MySQL bits after the sqlite3 BEGIN EXCLUSIVE returns? :-? -- ----- stephan beal http://wanderinghorse.net/home/stephan/ http://gplus.to/sgbeal _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
