Re: Quote from comp.object

On 2007-02-28, Aloha Kakuikanu wrote:

> 2. Extracting all children of a parent record by foreign key index
> versus extracting children by direct references. Logarithmic cost
> versus constant which is also not a big deal.

There is no reason why you couldn't implement hashed (i.e. finely partitioned) storage, physical links and/or clusters/materialized joins in an RDBMS. All of them push the cost downto O(1). The only difference is, under a real RDBMS such physical optimizations are hidden from the application. Furthermore, if you really want, you can even cut down on the constant term -- System R already employed precompilation and a low level interface for that sort of thing. Hence, the RM places little to no constraints on optimization.

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Sampo Syreeni, aka decoy - mailto:decoy_at_iki.fi, tel:+358-50-5756111
student/math+cs/helsinki university, http://www.iki.fi/~decoy/front
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