From: Dmitry Lenev Date: June 19 2012 7:53pm Subject: Re: purpose of thd_mark_transaction_to_rollback List-Archive: http://lists.mysql.com/internals/38535 Message-Id: <20120619195350.GB11468@jubjub> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Hello Zardosht! * Zardosht Kasheff [12/06/19 22:20]: > Hello all, > > What is the purpose of thd_mark_transaction_to_rollback? This call allows storage engine to request a transaction/statement rollback from SQL-layer. For example, when InnoDB storage engine detects a deadlock it rolls back the transaction inside storage engine (i.e. itself), but it still needs to invoke this method so transaction is properly rolled back in other storage engines (including binary log). > Under what conditions is a storage engine required to call this function? See above. I guess it is good idea to call this method when your storage engine decides to initiate a transaction rollback because of internal reasons, i.e. in case when such a rollback is not explicitly initiated from SQL-layer. Hope this helps! -- Dmitry Lenev, Software Developer Oracle Development SPB/MySQL, www.mysql.com Are you MySQL certified? http://www.mysql.com/certification