Dmitry, we have to consider implementing
NOWAIT and SKIP LOCKED clauses to SQL statements. The latter would be useful in implementing transactional queues. But there are lots of items in the TODO list. Do not expect these soon. Best regards, Heikki Tuuri Innobase Oy http://www.innodb.com Foreign keys, transactions, and row level locking for MySQL InnoDB Hot Backup - hot backup tool for InnoDB which also backs up MyISAM tables Order MySQL technical support from https://order.mysql.com/ ----- Original Message ----- From: ""Dmitry Anikin"" <[EMAIL PROTECTED]> Newsgroups: mailing.database.myodbc Sent: Monday, December 15, 2003 11:26 AM Subject: Can I really have no_wait row-locks in MySQL+InnoDB? > Suppose some user issued 'select ... for update', then > went for coffee-break (to think hard on what he > really wants to update in that row). Another client > tries to update the same row and I don't want him to > wait, just immediately return an error, so he could > do some other useful task meanwhile. I haven't found > any no_wait option for locks in the manual :(. > > There's a variable innodb_lock_wait_timeout, though, but > unfortunately I can't assign 0 to it (min. value is 1). > Still, 1 second time-out can be bearable (although I'd > appreciate a way to reduce it to zero) but what disturbs > me is that I've read in the manual that deadlock-removing > algorithm aborts transaction which it thinks is most suitable > for aborting (not last-in-first-aborted). Since time-out > feature has something to do with deadlocks can I be > absolutely sure that WAITING transaction will be aborted > and not that which issued the lock? > And also it would be fine to have non-destructive means > to determine whether some row has been locked so I may > just skip (postpone) some updates without rollback > of whole transaction. Is it possible? > > > > -- > MySQL General Mailing List > For list archives: http://lists.mysql.com/mysql > To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED] > -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
