[ale] MySQL question on indexes

[Greg Sabino Mullane]

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> Is it possible to create an index using a function, like upper() or
> ucase() or whatever?

This is what is known as a functional index. Last I checked, MySQL 
does not have this. Matter of fact, all it has is simple b-tree 
indexes. Functional indexes are very handy things to have around: 
they let your run a function (even ones much more complcated than the 
examples above) one time only; after that, the results are available via 
the index for very fast lookups. It's not something you can really implement 
any other way and get the same benefits.

> I'm converting an old DOS Foxpro app with standard 
> dbase tables to a Windows app using MySQL as the backend

Ah, there's the problem. You're attempting to go from a RDBMS to 
a non-RDBMS. Hopefully the functional index is the only real 
difference, and hopefully you're using for something where data 
integrity is not important, such as serving up web pages.

Greg Sabino Mullane  greg at turnstep.com
PGP Key: 0x14964AC8 200203051348

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