Philip Zeyliger has uploaded a new patch set (#2). Change subject: IMPALA-5211: Simplifying conditionals (istrue, nullif, etc.) ......................................................................
IMPALA-5211: Simplifying conditionals (istrue, nullif, etc.) This commit simplifies the following conditional functions: * istrue * isfalse * isnottrue * isnotfalse * zeroifnull * nullifzero * nullvalue * nonnullvalue * nullif Most of these simplifications work when the arguments to these functions are literals. The one exception is that nullif(x, y) simplifies to NULL when x.equals(y) as expressions. This is valid since nullif(null, null)=null. This simplification has not been applied to the equivalent "case x=x then null else null". In terms of the implementation is a bit of a toss-up between re-writing these into their equivalent case statements or simplifying them here. Testing: * Added new tests to ExprRewriteRulesTest * Confirmed (using EclEmma, which uses jococo engine) that coverage is good. Change-Id: Id91ca968a0c0be44e1ec54ad8602f91a5cb2e0e5 --- M fe/src/main/java/org/apache/impala/rewrite/SimplifyConditionalsRule.java M fe/src/test/java/org/apache/impala/analysis/ExprRewriteRulesTest.java 2 files changed, 200 insertions(+), 18 deletions(-) git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/29/7829/2 -- To view, visit http://gerrit.cloudera.org:8080/7829 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: newpatchset Gerrit-Change-Id: Id91ca968a0c0be44e1ec54ad8602f91a5cb2e0e5 Gerrit-PatchSet: 2 Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-Owner: Philip Zeyliger <[email protected]>
