Lee pointed me to this staging with my update-innobase-1.0.7 branch: http://hudson.drizzle.org/view/Drizzle-staging/job/drizzle-staging-drizzleslap/717/console
Which shows a bunch of "Lock wait timeout exceeded; try restarting transaction" on UPDATE T1 SET ... WHERE id = X statements. I've bisected this back to this revision: revno: 2106 author: Marko Mäkelä <[email protected]> committer: Stewart Smith <[email protected]> branch nick: update-innobase timestamp: Sat 2010-10-16 00:26:24 +1100 message: Merge Revision revid:[email protected] from MySQL InnoDB Original revid:[email protected] Original Authors: Marko Mkel <[email protected]> Original commit message: row_search_for_mysql(): Never try semi-consistent read in unique searches. They are only useful in table scans. (Bug #52663) Which gives you an idea. Marko's description in the bug report is possibly the best: > A short description of the fix for the documentation: Never try > semi-consistent read in > unique searches. They are only useful in table scans. > >Some context: Semi-consistent read was implemented in order to address >Bug #3300. Semi-consistent reads do not block when a non-matching record >is already locked by some other transaction. If the record is not >locked, a lock will be acquired, but it will be released if the record >does not match the WHERE condition. This bug was that semi-consistent >read was attempted even for UPDATEs whose WHERE condition is of the form >pk_col1=constant1,…,pk_colN=constantN. Some code that was built with the >assumption that semi-consistent read would be only attempted on table >scans, failed. For us, this probably doesn't help either: https://bugs.launchpad.net/drizzle/+bug/587772 "READ COMMITTED isolation level doesn't work (at least with InnoDB)" I welcome thoughts. I'm thinking that the lock wait timeouts are likely correct... -- Stewart Smith _______________________________________________ Mailing list: https://launchpad.net/~drizzle-discuss Post to : [email protected] Unsubscribe : https://launchpad.net/~drizzle-discuss More help : https://help.launchpad.net/ListHelp
