Impala Public Jenkins has submitted this change and it was merged. ( http://gerrit.cloudera.org:8080/8660 )
Change subject: IMPALA-5929: Remove redundant explicit casts to string ...................................................................... IMPALA-5929: Remove redundant explicit casts to string This patch adds a query rewriter to remove redundant explicit casts to a string type (string, char, varchar) from binary predicates of the form "cast(<non-const expr> to <string type>) <eq/ne op> <string constant>". The cast is redundant if the predicate evaluation is the same even if the cast is removed and the constant is converted to the original type of the expression. For example: cast(int_col as string) = '123456' -> int_col = 123456 Performance: For the following query on a table having 6001215 records - select * from tpch.lineitem where cast(l_linenumber as string) = '0' +-----------------+-----------+--------+ | | Scan Time | +-----------------+-----------+--------+ | | Avg | St dev | | Without rewrite | 1s406ms | 44ms | | With rewrite | 1s099ms | 28ms | +-----------------+-----------+--------+ Testing: - Added unit tests to ExprRewriteRulesTest - Added functional test to expr.test - Current FE planner tests and BE expr-test run successfully with this change. Change-Id: I91b7c6452d0693115f9b9ed9ba09f3ffe0f36b2b Reviewed-on: http://gerrit.cloudera.org:8080/8660 Reviewed-by: Dimitris Tsirogiannis <[email protected]> Tested-by: Impala Public Jenkins --- M fe/src/main/java/org/apache/impala/analysis/Analyzer.java A fe/src/main/java/org/apache/impala/rewrite/RemoveRedundantStringCast.java M fe/src/test/java/org/apache/impala/analysis/ExprRewriteRulesTest.java M testdata/workloads/functional-query/queries/QueryTest/exprs.test 4 files changed, 196 insertions(+), 1 deletion(-) Approvals: Dimitris Tsirogiannis: Looks good to me, approved Impala Public Jenkins: Verified -- To view, visit http://gerrit.cloudera.org:8080/8660 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: merged Gerrit-Change-Id: I91b7c6452d0693115f9b9ed9ba09f3ffe0f36b2b Gerrit-Change-Number: 8660 Gerrit-PatchSet: 6 Gerrit-Owner: Bikramjeet Vig <[email protected]> Gerrit-Reviewer: Alex Behm <[email protected]> Gerrit-Reviewer: Bikramjeet Vig <[email protected]> Gerrit-Reviewer: Dimitris Tsirogiannis <[email protected]> Gerrit-Reviewer: Impala Public Jenkins Gerrit-Reviewer: Thomas Tauber-Marshall <[email protected]> Gerrit-Reviewer: Tim Armstrong <[email protected]>
