[teiid-issues] [JBoss JIRA] (TEIID-3009) perform projection minimization on with commands
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https://issues.jboss.org/browse/TEIID-3009?page=com.atlassian.jira.plugin...
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Steven Hawkins resolved TEIID-3009.
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Resolution: Done
The logic here will replace any unused projection with a null value - to keep the
definition of the cte consistent. The logic is not quite as clean as I would like as
it's done in a preprocessing step in relationalplanner and requires some temp plans
and additional runs of ruleassignoutputelements. The optimization is not completely deep.
Usage of a CTE in any subquery (including other CTEs) will be seen as required -
regardless of whether the subquery will actually exist in the final plan form. We'd
need better iterative facilities to do any better as that would currently be quite
expensive.
This commit also corrected an issue with the assignment of with clauses to pushdown
queries. The old code did not deeply check for usage.
perform projection minimization on with commands
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Key: TEIID-3009
URL: https://issues.jboss.org/browse/TEIID-3009
Project: Teiid
Issue Type: Sub-task
Security Level: Public(Everyone can see)
Components: Query Engine
Reporter: Steven Hawkins
Assignee: Steven Hawkins
Fix For: 8.9
We currently treat the with clause as the creation of a temporary table at a query scope,
but we can do projection minimization based upon the referenced columns. This is somewhat
tricky with the current planning logic as we must first plan the with clause to determine
if it's eligible for pushdown to then plan the main command.
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