Jim Apple has uploaded a new patch set (#4). Change subject: IMPALA-2581: LIMIT can be propagated down into some aggregations ......................................................................
IMPALA-2581: LIMIT can be propagated down into some aggregations SELECT DISTINCT f FROM t LIMIT n Can pass the LIMIT all the way down to the pre-aggregation, which leads to a nearly unbounded speedup on these queries in large tables when n is low. Queries like SELECT f, COUNT(*) FROM t GROUP BY f LIMIT n cannot pass the LIMIT down to the pre-aggregation, and so experience a smaller speedup. Change-Id: I59c5b7af7a73ccdbc5496b28eacb9b6859d202bc --- M be/src/exec/exec-node.h M be/src/exec/partitioned-aggregation-node-ir.cc M be/src/exec/partitioned-aggregation-node.cc M be/src/exec/partitioned-aggregation-node.h M fe/src/main/java/com/cloudera/impala/analysis/AggregateInfoBase.java M fe/src/main/java/com/cloudera/impala/planner/DistributedPlanner.java M testdata/workloads/functional-planner/queries/PlannerTest/aggregation.test M testdata/workloads/functional-planner/queries/PlannerTest/tpcds-all.test M testdata/workloads/functional-query/queries/QueryTest/spilling.test M testdata/workloads/targeted-perf/queries/aggregation.test 10 files changed, 87 insertions(+), 11 deletions(-) git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/22/3822/4 -- To view, visit http://gerrit.cloudera.org:8080/3822 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: newpatchset Gerrit-Change-Id: I59c5b7af7a73ccdbc5496b28eacb9b6859d202bc Gerrit-PatchSet: 4 Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-Owner: Jim Apple <[email protected]> Gerrit-Reviewer: Alex Behm <[email protected]> Gerrit-Reviewer: Jim Apple <[email protected]> Gerrit-Reviewer: Matthew Jacobs <[email protected]> Gerrit-Reviewer: Tim Armstrong <[email protected]>
