On 24/05/13 15:57, George Gallen wrote: > In thinking about it....I'm not sure, but it seems to increase the selection > speed (considerably). It is a type 30 file, > So possibly the index makes up for a hashing algorithm where the modulo is > too small? And the makeup of > The @ID causing more similar hashing?
A type 30 file typically is very well balanced. Bear in mind that UV files store the key with the data in the group (unless the record is "large"). So any unindexed select has to scan the entire file. So an index will speed up any select, simply by reducing massively the amount of i/o required. I guess it acts strange with an index on @ID because such an index needs special code, precisely because it's not indexing a data field... Cheers, Wol _______________________________________________ U2-Users mailing list U2-Users@listserver.u2ug.org http://listserver.u2ug.org/mailman/listinfo/u2-users
