On Tue, Nov 9, 2010 at 7:47 PM, Justin Swanhart <greenl...@gmail.com> wrote: > This is kind of unrelated, but it seems like a good thread to ask the > question in. > > Are there any plans to make an indexed virtual column work > automatically as an index for the table? Other databases support > 'functional' indexing, that is, you can index the contents of a > function call and the if you use that function call in the where > clause, then the index is automatically used. > > For example: > select * from some_table where UPPER(some_col) = 'ABC' > > In order to avoid a FTS you could create an indexed persistent virtual > column for UPPER(some_col) and modify your SQL to use it. It would, > however, be much nicer if the optimizer could detect a virtual column > which matches the function call and use the index automatically if one > exists on the virtual column, or scan the virtual column if it > doesn't. > > Likely this could be done in the same phase as 'constant replacement'. > If an expression exactly matches a virtual column, replace the > expression with a reference to the virtual column. If the virtual > column is indexed, then the index should get automatically used, > otherwise it will get scanned.
I'm not aware of additional work being done related to this right now. I understand what you suggest, but let's face it, this would just be a convenience feature for those that are too lazy to rewrite their queries to actually use the virtual column :-) Even if I'm not a minimalist when it comes to features, I think what you suggest is probably stretching the MySQL tradition of being simple and straightforward. henrik -- henrik.i...@avoinelama.fi +358-40-5697354 www.openlife.cc _______________________________________________ Mailing list: https://launchpad.net/~maria-discuss Post to : maria-discuss@lists.launchpad.net Unsubscribe : https://launchpad.net/~maria-discuss More help : https://help.launchpad.net/ListHelp
