Alex Behm has posted comments on this change. Change subject: IMPALA-5003: Constant propagation in scan nodes ......................................................................
Patch Set 18: (4 comments) Basically done, final nits http://gerrit.cloudera.org:8080/#/c/6389/18//COMMIT_MSG Commit Message: Line 7: IMPALA-5003: Constant propagation in scan nodes Constant propagation in scan conjuncts Line 9: When conjuncts are pushed into table refs from inline views, they can Wording is slightly confusing because we don't "push conjuncts into table refs", we have specific terms for those things. How about saying something like (amend as you see fit obviously): Implements constant propagation within a list of conjuncts and applies the optimization to scan conjuncts. The optimization is applied during planning to take the complete list of applicable conjuncts into account. In particular, we want to simplify conjuncts to enable partition pruning.... http://gerrit.cloudera.org:8080/#/c/6389/18/fe/src/main/java/org/apache/impala/analysis/Expr.java File fe/src/main/java/org/apache/impala/analysis/Expr.java: Line 922: // Arbitrary cost bound for propagation How about: // Arbitrary max number of exprs considered during constant propagation to limit the cost due to the O(N^2) complexity. Line 923: private final static int CONST_PROPAGATION_LIMIT = 200; CONST_PROPAGATION_EXPR_LIMIT -- To view, visit http://gerrit.cloudera.org:8080/6389 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: comment Gerrit-Change-Id: I79750a8edb945effee2a519fa3b8192b77042cb4 Gerrit-PatchSet: 18 Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-Owner: Zach Amsden <[email protected]> Gerrit-Reviewer: Alex Behm <[email protected]> Gerrit-Reviewer: Dan Hecht <[email protected]> Gerrit-Reviewer: Marcel Kornacker <[email protected]> Gerrit-Reviewer: Zach Amsden <[email protected]> Gerrit-HasComments: Yes
