Aleksandr Efimov has uploaded this change for review. ( http://gerrit.cloudera.org:8080/24896
Change subject: IMPALA-15381: Reduce reservoir RNG state ...................................................................... IMPALA-15381: Reduce reservoir RNG state boost::mt19937_64 makes ReservoirSampleState 2536 bytes. FreePool rounds the allocation to 4 KiB, so sampling aggregates use 4624 bytes per function and group with their initial sample array. Use pcg32 to reduce the state to 48 bytes and keep the planner estimate introduced by IMPALA-13052 in sync. The sampling sequence changes, so approximate results can change. Testing: - Full release build - HistogramTest.* Change-Id: I9e046e3f0c1b91f1761ce578601a330bd864eb84 Assisted-by: gpt-5.6-sol (OpenAI Codex) --- M be/src/exprs/aggregate-functions-ir.cc M fe/src/main/java/org/apache/impala/planner/AggregationNode.java 2 files changed, 13 insertions(+), 18 deletions(-) git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/96/24896/1 -- To view, visit http://gerrit.cloudera.org:8080/24896 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: newchange Gerrit-Change-Id: I9e046e3f0c1b91f1761ce578601a330bd864eb84 Gerrit-Change-Number: 24896 Gerrit-PatchSet: 1 Gerrit-Owner: Aleksandr Efimov <[email protected]>
