On Tue, Feb 21, 2006 at 10:27:15AM +0900, Tatsuo Ishii wrote: > If you consider to allow only UTF-16 or whatever encoding in backend, > I will strongly against the idea. We Japanese need those encodings > native support. Converting those encodings with Unicode everytime when > backend and forntend have conversations will be serious performance > hit. Moreover the converion is known as not being roundtrip safe, that > means some information will be lost during the conversion. The another > point would be on disk format. UTF-16 will require more storage than > local encodings. Probably UTF-8 will require more. I didn't say that we only support utf-16 in the backend, I said that when doing comparisons in a non-C locale, you have to convert to UTF-16 to use ICU. If you don't want to use it, don't, it's not going to be required at any point. Just like currently with Win32, if you use UTF-8 it has to be converted to UTF-16 prior to string comparison. The only time any of this is required is *sorting* and if you have an index defined it acts as a cache for the sorted values. Ofcourse there's a tradeoff but unless you're sorting large datasets all day I doubt it'll be noticable. If you're not sorting, none of this is relevent to you. > I have a feeling that ICU is good for applications, but is not for > DBMSs. I think providing a system where users are able to select out of a large range of possible collation orders and if necessary specify their own is a worthy goal. Look at the complaints we get now and then of people who choose en_US as their locale and are surprised when it gives them a dictionary sort. ICU allows users to take an existing collation and tweak it if it doesn't quite match their expectations. You think this is not useful for a DBMS? Have a nice day, -- Martijn van Oosterhout <kleptog@xxxxxxxxx> http://svana.org/kleptog/ > Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a > tool for doing 5% of the work and then sitting around waiting for someone > else to do the other 95% so you can sue them.
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