[teiid-issues] [JBoss JIRA] Resolved: (TEIID-1272) Join planning should make better decisions when mixing costing and unknown values
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https://jira.jboss.org/browse/TEIID-1272?page=com.atlassian.jira.plugin.s...
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Steven Hawkins resolved TEIID-1272.
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Resolution: Done
updated the join ordering logic to better use the known side cost when determining the
join order. I did not change the base join costing logic as that could lead to bad
dependent join logic (but there still is room for improvement).
Join planning should make better decisions when mixing costing and
unknown values
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Key: TEIID-1272
URL: https://jira.jboss.org/browse/TEIID-1272
Project: Teiid
Issue Type: Quality Risk
Components: Query Engine
Affects Versions: 7.0
Reporter: Steven Hawkins
Assignee: Steven Hawkins
Fix For: 7.1.1
When faced with an unknown value during join planning we use the default assumption of
100000 rows. However this may cause non-performant cross joins to be pushed in the worst
case. It would be better to either not cost these scenarios or get a more accurate
estimate of the post join cardinality based upon the the other side of the join.
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