[jira] [Created] (DERBY-6954) Allow plans to execute where HASH tables are estimated to spill to disk.

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[jira] [Created] (DERBY-6954) Allow plans to execute where HASH tables are estimated to spill to disk.

JIRA jira@apache.org
Harshvardhan Gupta created DERBY-6954:
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             Summary: Allow plans to execute where HASH tables are estimated to spill to disk.
                 Key: DERBY-6954
                 URL: https://issues.apache.org/jira/browse/DERBY-6954
             Project: Derby
          Issue Type: Sub-task
            Reporter: Harshvardhan Gupta


Derby Optimizer currently rejects the plans where it estimates that intermediate HASH Tables in HASH Joins will spill to disk. We need to model the cost associated of HASH Join disk spill in order to make them a candidate for optimal plan. DERBY-6938, DERBY-1259 and DERBY-106 contain some useful details around this behaviour.

One possible workaround around this behaviour is to explicitly specify optimizer hints and overriding the default optimizer behaviour.
https://db.apache.org/derby/docs/10.13/tuning/ctunoptimzoverride.html




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