I have spent some of my spare time looking into this. It turns out that MySQL Cluster already has this ability. They have the following handler functions listed below. I spent a weekend trying to port MySQL Cluster's alter table function (mysql_alter_table) over to 5.1.46.
The port that I did was straightforward, and for the most part, it works. There are a couple of small bugs/issues that I need to investigate and track down, but the functionality is available. If this can be made to work in a safe way, where storage engines can choose whether to use MySQL Cluster's new alter table, and others use the existing, it seems like a very safe thing to integrate into 5.1. One problem I have run into is that I do not know how to get a storage engine to opt in. This was the motivation behind the following email to the MySQL internals alias. http://lists.mysql.com/internals/38105 For those curious, the issues that I have: - alter table on partitioned tables is returning ER_OUTOFMEMORY (This may only be when adding/dropping indexes) - All storage engines use the new alter table, I want storage engines to opt in, to reduce the risk of bugs Any thoughts? -Zardosht virtual int check_if_supported_alter(TABLE *altered_table, HA_CREATE_INFO *create_info, HA_ALTER_FLAGS *alter_flags, uint table_changes) virtual int alter_table_phase1(THD *thd, TABLE *altered_table, HA_CREATE_INFO *create_info, HA_ALTER_INFO *alter_info, HA_ALTER_FLAGS *alter_flags) virtual int alter_table_phase2(THD *thd, TABLE *altered_table, HA_CREATE_INFO *create_info, HA_ALTER_INFO *alter_info, HA_ALTER_FLAGS *alter_flags) virtual int alter_table_phase3(THD *thd, TABLE *table) On Wed, Sep 22, 2010 at 2:28 PM, MARK CALLAGHAN <mdcal...@gmail.com> wrote: > It would be even cooler if there were storage engines that could do > this internally. That would be easier to manage. The current process > requires that you validate that your version of MariaDB or MySQL does > the right thing for the tool. > > Note that the tool does a few steps differently for 5.0 versus 5.1 > because behavior has changed. > > On Tue, Sep 21, 2010 at 7:41 PM, Adam M. Dutko <dutko.a...@gmail.com> wrote: >> I'm sure you have all >> read http://bazaar.launchpad.net/~mysqlatfacebook/mysqlatfacebook/tools/annotate/head:/osc/OnlineSchemaChange.php already, >> but if you haven't, it might be neat to look at evaluating and possibly >> integrating it into MariaDB. >> _______________________________________________ >> Mailing list: https://launchpad.net/~maria-developers >> Post to : maria-developers@lists.launchpad.net >> Unsubscribe : https://launchpad.net/~maria-developers >> More help : https://help.launchpad.net/ListHelp >> >> > > > > -- > Mark Callaghan > mdcal...@gmail.com > > _______________________________________________ > Mailing list: https://launchpad.net/~maria-developers > Post to : maria-developers@lists.launchpad.net > Unsubscribe : https://launchpad.net/~maria-developers > More help : https://help.launchpad.net/ListHelp > _______________________________________________ Mailing list: https://launchpad.net/~maria-developers Post to : maria-developers@lists.launchpad.net Unsubscribe : https://launchpad.net/~maria-developers More help : https://help.launchpad.net/ListHelp
