Hi, Simon! On Dec 27, Simon J Mudd wrote: > > Slightly off topic but changes in sql_mode has the potential to cause > problems with major version changes and incompatible behaviour. So > combining all sorts of new settings into this variable does not seem > like a good idea to me. It’s already rather complex.
Yes, precisely. I thought today what should be the criteria for choosing between a new sql mode or a separate variable, like @@concat_null_is_null. And I realized that one such criteria could be - does it need to be stored *per routine*? Saved with every storage procedure, function, trigger and event definition? > Note: don’t just think of how the server behaves with this change but > also think of replication. Downstream slaves may not be running the > same (major or minor) version of MariaDB (or MySQL) and sql_mode is > fed into the binlog stream so will be interpreted by the SQL thread(s) > of the downstream slaves too. > > I’d be much more comfortable using a new global variable which defines > this behaviour, though that _may_ require the setting being propagated > via the binlog stream if setting the value globally on the downstream > slave is not good enough. I think that a global variable does not solve the replication issue, when slaves are of a different version. When slaves don't implement this configurable option (whether sql_mode or a separate variable), the only way for replication to work is not to change this option on the master. It means that for a new sql_mode the default backward compatible behavior should be "new sql mode is not set" and for the global variable the default value should provide the compatible behavior. Although a global variable does provide a benefit that only a SUPER user can change it (and thus break the replication). Regards, Sergei Chief Architect MariaDB and [email protected] _______________________________________________ Mailing list: https://launchpad.net/~maria-developers Post to : [email protected] Unsubscribe : https://launchpad.net/~maria-developers More help : https://help.launchpad.net/ListHelp
