From: Dmitry Lenev Date: April 11 2011 9:29am Subject: Re: allowing other threads to write to a table during "create index" List-Archive: http://lists.mysql.com/internals/38294 Message-Id: <20110411092938.GJ1036@bandersnatch> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Hello, Zardosht! * Zardosht Kasheff [11/04/09 03:43]: > In MySQL 5.1, a storage engine can allow other threads to write to a > table while an index (via handler::add_index) is being created. To do > so, one can set the lock_type to TL_WRITE_ALLOW_WRITE when > handler::store_lock is called. > > In MySQL 5.5, this does not work, because a "metadata lock", or MDL > has been added to the system. Is there any way to get this to work in > MySQL 5.5? I don't think it is possible to do this in MySQL 5.5. We work on alleviating this issue in future releases. -- Dmitry Lenev, Software Developer Oracle Development SPB/MySQL, www.mysql.com Are you MySQL certified? http://www.mysql.com/certification