Michael Smith has uploaded a new patch set (#11) to the change originally
created by Qifan Chen. ( http://gerrit.cloudera.org:8080/18458 )
Change subject: IMPALA-11274: CNF Rewrite causes a regress in join node
performance
......................................................................
IMPALA-11274: CNF Rewrite causes a regress in join node performance
This patch defines a subset of all predicates that are common and
relatively inexpensive to compute. Such predicates must involve
columns, constants, simple math or cast functions only.
Examples of the subset of the predicates allowed:
1. (a = 1 AND cast(b as int) = 2) OR (c = d AND e = f)
2. a in ('1', '2', '3') OR ((b = 'abc') AND (c = d))
3. (a between 1 and 100) OR ((b is null) AND (c = d))
Examples of the predicates not allowed:
1. (upper(a) != 'Y') AND b = 2) OR (c = d AND e = f)
2. (coalesce(CAST(a AS string), '') = '') AND b = 2) OR
(c = d AND e = f)
This patch further restricts the predicates to be converted to
conjunctive normal form (CNF) to be such a subset, with the aim to
reduce the run-time evaluation overhead of CNFs in which some
of the predicates can be duplicated.
Uses a cache in Predicates to avoid visiting the entire subtree on each
call to applyRuleBottomUp. Skips cache complexity on casts as they don't
branch and are unlikely to be deeply nested.
Testing:
1. Added a new test TestFeasibleToConvertToCNF() in ExprRewriterTest.java
3. perf-AB-test
Change-Id: I326406c6b004fe31ec0e2a2f390a3845b8925aa9
---
M fe/src/main/java/org/apache/impala/analysis/CastExpr.java
M fe/src/main/java/org/apache/impala/analysis/ExistsPredicate.java
M fe/src/main/java/org/apache/impala/analysis/Expr.java
M fe/src/main/java/org/apache/impala/analysis/FunctionCallExpr.java
M fe/src/main/java/org/apache/impala/analysis/IsNotEmptyPredicate.java
M fe/src/main/java/org/apache/impala/analysis/LikePredicate.java
M fe/src/main/java/org/apache/impala/analysis/Predicate.java
M fe/src/main/java/org/apache/impala/analysis/SlotRef.java
M fe/src/main/java/org/apache/impala/analysis/TupleIsNullPredicate.java
M fe/src/main/java/org/apache/impala/rewrite/ConvertToCNFRule.java
M fe/src/test/java/org/apache/impala/analysis/ExprRewriterTest.java
M
testdata/workloads/functional-planner/queries/PlannerTest/constant-folding.test
M testdata/workloads/functional-planner/queries/PlannerTest/convert-to-cnf.test
13 files changed, 204 insertions(+), 9 deletions(-)
git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/58/18458/11
--
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Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-MessageType: newpatchset
Gerrit-Change-Id: I326406c6b004fe31ec0e2a2f390a3845b8925aa9
Gerrit-Change-Number: 18458
Gerrit-PatchSet: 11
Gerrit-Owner: Qifan Chen <qc...@cloudera.com>
Gerrit-Reviewer: Aman Sinha <amsi...@cloudera.com>
Gerrit-Reviewer: Impala Public Jenkins <impala-public-jenk...@cloudera.com>
Gerrit-Reviewer: Kurt Deschler <kdesc...@cloudera.com>
Gerrit-Reviewer: Michael Smith <michael.sm...@cloudera.com>
Gerrit-Reviewer: Qifan Chen <qc...@cloudera.com>
Gerrit-Reviewer: Quanlong Huang <huangquanl...@gmail.com>
