Oracle FAQ Your Portal to the Oracle Knowledge Grid
HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US
 

Home -> Community -> Usenet -> comp.databases.theory -> Re: Nested Sets vs. Nested Intervals

Re: Nested Sets vs. Nested Intervals

From: <amado.alves_at_netcabo.pt>
Date: 11 Nov 2005 02:54:22 -0800
Message-ID: <1131706462.089883.234450@g14g2000cwa.googlegroups.com>


"...a special entity (node) 'RangeForLessThan(constant) to the data model for every imaginable constant ?"

Of course not. Even RangeForLessThan is clearly to see that it is an function.

Note that actually using ranges instead of boolean conditions keeps the language simpler, because you don't introduce boolean conditions. A range function is an algebraic operator like T, S.

You you're just trying to find problems in my system let me save you some time: Mneson Calculus expressions for complex queries are hard to follow and construct; a better query language with proper linguistic devices for the semantic structures must be selected or created; then mapped onto Mneson Calculus for query planning, optimization, evaluation; here operations must be optimized; I have suceeded in optimizing expressions like T(K1)^T(K2) where K1, K2 are known (e.g. constants) but I am still looking for ways to optimize expressions like T(T(...)) Received on Fri Nov 11 2005 - 04:54:22 CST

Original text of this message

HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US