Marcel Kornacker has posted comments on this change. Change subject: IMPALA-2805: Order conjuncts based on selectivity and cost ......................................................................
Patch Set 13: (1 comment) http://gerrit.cloudera.org:8080/#/c/2598/13/fe/src/main/java/com/cloudera/impala/planner/PlanNode.java File fe/src/main/java/com/cloudera/impala/planner/PlanNode.java: Line 663: sel = Math.pow(Expr.DEFAULT_SELECTIVITY, backoff_exp); > hm, we're now applying the default selectivity multiple times and independe actually, a decent first approach might be to distribute the default selectivity evenly across all predicates in the list with no selectivity. that's kind of what we assume in the join planning (that all predicates w/o selectivity for a particular operator have a combined selectivity = default selectivity). -- To view, visit http://gerrit.cloudera.org:8080/2598 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: comment Gerrit-Change-Id: I02279a26fbc6308ac5eb819d78345fc010469034 Gerrit-PatchSet: 13 Gerrit-Project: Impala Gerrit-Branch: cdh5-trunk Gerrit-Owner: Thomas Tauber-Marshall <[email protected]> Gerrit-Reviewer: Alex Behm <[email protected]> Gerrit-Reviewer: Henry Robinson <[email protected]> Gerrit-Reviewer: Marcel Kornacker <[email protected]> Gerrit-Reviewer: Matthew Jacobs <[email protected]> Gerrit-Reviewer: Mostafa Mokhtar <[email protected]> Gerrit-Reviewer: Thomas Tauber-Marshall <[email protected]> Gerrit-HasComments: Yes
