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Posted to dev@drill.apache.org by "Jason Altekruse (JIRA)" <ji...@apache.org> on 2015/04/07 01:08:12 UTC
[jira] [Created] (DRILL-2702) Support more advanced constant
expression folding
Jason Altekruse created DRILL-2702:
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Summary: Support more advanced constant expression folding
Key: DRILL-2702
URL: https://issues.apache.org/jira/browse/DRILL-2702
Project: Apache Drill
Issue Type: Improvement
Components: Query Planning & Optimization
Reporter: Jason Altekruse
Assignee: Jinfeng Ni
A variety of constant expressions are now folded at planning time with the work completed for DRILL-2060. One of the examples listed in the issue is not currently supported. Supporting an expression re-write like this will require more work, this issue is here to track that enhancement request. These types of rewrites are particularly useful for Drill because the speed of Drill is often limited by the types of filter pushdowns supported by the underlying storage system. For system that support range scans, we can rewrite inequalities to range scans in simple cases. Currently we cannot re-write more complicated inequalities like this one below, this query would prompt a full table scan with a filter, but the transformation shown can turn it into a range scan.
Where age + 5 < 42
can be re-written as
Where age < 37
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