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From Daniel John Debrunner <...@apache.org>
Subject Re: [jira] Commented: (DERBY-1315) largeCodeGen fails with embedded and framework DerbyNetClient
Date Wed, 09 Aug 2006 00:16:15 GMT
Army wrote:

> Daniel John Debrunner wrote:
> 
>>
>> Any pointers to the type of extra state kept around. Is it query tree
>> nodes, collections, something else?
> 
> 
> With Phase 1 of DERBY-805, a HashMap was added to each query tree node. 
> The map holds an Object->AccessPathImpl mapping for each OptimizerImpl
> that occurs above the node in the query tree.  The "Object" in this
> mapping is an object that already existed; the AccessPathImpl is a new
> object.
> 
> See FromTable.addOrLoadBestPlanMapping()
> 
> With Phase 4, additional entries to the HashMap are added for every
> UnionNode, PRN, or JoinNode that occurs above the node...and also for
> every occurrence of a node that doesn't implement "optimizeIt()". 

I don't see anything ever being removed from these hashMaps. Is it
possible to remove entries at any time?

Dan.






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