Of Character Sets, Performance and Storage...

I've got this data warehouse with an nls_characterset of WE8ISO8859P1 and an nls_nchar_characterset of AL16UTF16 but all the stored data is only US-ASCII. (The data is from Apache logs capturing tons of web application activity much of which comes from URI's which by W3C definition is US-ASCII.)

The Oracle9i Globalization manual states: "Single-byte character sets result in better performance than multi-byte character sets, and they are also more efficient in terms of space requirements."

So... The obvious question is, How much more efficient and better performing are they in actual practice? Also, I'm thinking US7ASCII and WE8ISO8859P1 are both single-byte and possess equivalent storage requirements and performance characteristics even though one is 7 bit and the other is 8 bit. Is this true?

The current DW is not too big to recreate in the downsized US7ASCII character set but is it even worth it? The DW will be getting quite large so it's important now to address the bits and bytes storage and performance concerns.

Of Mice and DBA's,
Steve Orr,
Bozeman, Montana

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