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https://issues.jboss.org/browse/TEIID-1474?page=com.atlassian.jira.plugin...
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Steven Hawkins commented on TEIID-1474:
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To round out the proposal:
Would the hint also affect joins to force serial execution?
Can the hint appear anywhere above the union (through 1 or more view layers), or would it
have to be located on the union query?
What heuristics would we apply to determine the firing order of branches?
Add query hint to limit parallel execution of union members
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Key: TEIID-1474
URL:
https://issues.jboss.org/browse/TEIID-1474
Project: Teiid
Issue Type: Feature Request
Reporter: Howard Abrams
Assignee: Steven Hawkins
We would like a new query hint to limit the number of parallel executions of union
members. This is useful in two situations:
1. When the queries are expensive, but the overall union contains a limit that is most
likely to be fulfilled by the first member of the union
2. When the queries are backed by a common resource which may be overloaded by multiple
queries
The addition of a hint would make this manageable by the client; perhaps something like
"/*+ parallel=2*/"?
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