Re: foundations of relational theory?
Date: Thu, 30 Oct 2003 02:17:00 GMT
Message-ID: <ww_nb.59317$Tr4.141427_at_attbi_s03>
"Anthony W. Youngman" <thewolery_at_nospam.demon.co.uk> wrote in message news:VnHGwdHq$Fo$Ew0I_at_thewolery.demon.co.uk...
>
> You saw my stats and reference to "1.05"? Given a request by the app,
> this is the number of times a MV database has to look (on average) to
> find the data the app requested.
If I understand your 1.05 correctly, then I don't think you are correct in thinking that 1.0 represents the theoretical minimum. By way of comparison, I once took over an ODBC driver codebase, and I was concerned about efficiency. One metric I used was remote procedure calls per odbc call. On the surface, it seems like the limit will be 1. When I took the project over, the number was about 1.5. When I finished some months later, the number was 0.2.
> The relational theory way of saying "we won't specify the implementation
> because we may find new ways of speeding it up" comes across as daft to
> the MV people who say "we can't make that figure less than one, and
> we're so close what's the point of trying to speed it up?"
Given your assumptions, that makes sense, but I think your assumptions are invalid.
Marshall Received on Thu Oct 30 2003 - 03:17:00 CET