Marcus Bointon wrote: Hi Marcus :)
> On 7 Mar 2007, at 08:44, Ian P. Christian wrote: > > --single-transaction doesn't _do_ the dump as a transaction, it simply > wraps the dump in begin/commit statements so it's atomic when restoring. > > If the dump is to preserve relational integrity then it has to lock > tables or disable access (or writes/deletes can happen during the dump). > There are two alternatives: One is to use innoDB's commercial hotbackup > utility (which I've not used, but it's apparently 'the way'). I was under the impression that with multi-versioning of InnoDB, that it wouldn't need to do a write lock? Sorry to quote this much from 'mysqldump --help'.... --master-data[=#] This causes the binary log position and filename to be appended to the output. If equal to 1, will print it as a CHANGE MASTER command; if equal to 2, that command will be prefixed with a comment symbol. This option will turn --lock-all-tables on, unless --single-transaction is specified too (in which case a global read lock is only taken a short time at the beginning of the dump - don't forget to read about --single-transaction below). In all cases any action on logs will happen at the exact moment of the dump.Option automatically turns --lock-tables off. --single-transaction Creates a consistent snapshot by dumping all tables in a single transaction. Works ONLY for tables stored in storage engines which support multiversioning (currently only InnoDB does); the dump is NOT guaranteed to be consistent for other storage engines. Option automatically turns off --lock-tables. I'll accept my interpritation of the above could be very wrong however... > The other > is one of the reasons for using a slave - stop the slave, do the dump, > restart the slave and it will catch up anything it missed. It helps if > you can dedicate a slave for this. Yes...I'm aware of this one, but alas.. this was my only slave, and it managed to become out of sync somehow (something to do with a bug when using 'mysqladmin kill'). Now I know that things like this happen, I'll take weekly snapshots of the slave data, but like I said - you live and learn :) Whilst I'm here and talking about slaves... is it possible to have a slave to 2 different databases on 2 different hosts? -- Ian P. Christian ~ http://pookey.co.uk -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
