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Posted to derby-commits@db.apache.org by Apache Wiki <wi...@apache.org> on 2006/11/07 23:49:46 UTC
[Db-derby Wiki] Trivial Update of "JoinOrderPermutations" by Army
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The following page has been changed by Army:
http://wiki.apache.org/db-derby/JoinOrderPermutations
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- costPermutation()
- This page describes the general flow of code as it occurs when a class such as !SelectNode or !TableOperatorNode calls the getNextPermutation() method of an !OptimizerImpl.
+ This page describes the general flow of code as it occurs when a class such as !SelectNode or !TableOperatorNode calls the getNextPermutation() method of an !OptimizerImpl. The expectation is that such a call will occur as part of a block of code similar to the following (copied from !SelectNode.optimize()):
+
+ {{{
+ /* Optimize this SelectNode */
+ while (optimizer.getNextPermutation())
+ {
+ while (optimizer.getNextDecoratedPermutation())
+ {
+ optimizer.costPermutation();
+ }
+ }
+ }}}
== In Short ==