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http://issues.apache.org/jira/browse/DERBY-855?page=comments#action_12364262 ]
Daniel John Debrunner commented on DERBY-855:
---------------------------------------------
This section is confusing to me:
constraint
The Derby optimizer chooses an index, including the indexes that enforce
constraints, as the access path for query execution if the index is useful. If
there is more than one useful index, in most cases Derby chooses the index that
is most useful.
I would expect the sentence after constraint to describe what this override
does, instead (I think) you are describing the default behaviour of the
optimizer. Scanning quickly through the docs I might assume that using
something like:
-- DERBY-PROPERTIES constraint=true
tells the optimizer to pick the best constraint for the query.
Also I don't know if we want something like the synax for the properties in
this list, e.g.
constraint=<constraint name>
...
index=<index name>
...
joinOrder={FIXED|UNFIXED}
> Document optimizer overrides which were introduced in 10.2
> ----------------------------------------------------------
>
> Key: DERBY-855
> URL: http://issues.apache.org/jira/browse/DERBY-855
> Project: Derby
> Type: Sub-task
> Components: Documentation
> Versions: 10.2.0.0
> Reporter: Mamta A. Satoor
> Assignee: Eric Radzinski
> Fix For: 10.2.0.0
> Attachments: ctundepthoptover.html, ctunoptimzoverride.html
>
> Optimizer overrides support in Derby was added as jira entry DERBY-573. Eric
> Radzinski is working on the documentation part of the feature. This issue is
> to keep track of documentation changes.
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