Todd Lipcon created KUDU-2381:
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Summary: Optimize DeltaMemStore for case of no matching deltas
Key: KUDU-2381
URL: https://issues.apache.org/jira/browse/KUDU-2381
Project: Kudu
Issue Type: Improvement
Components: perf, tablet
Reporter: Todd Lipcon
Assignee: Todd Lipcon
Currently in a scan workload which scans 280 columns I see DeltaMemStore
iteration taking up a significant amount of CPU in the scan, despite the fact
that the dataset has no updates. Of 1.6sec in MaterializingIterator::NextBlock,
we spent 0.61s in DMSIterator::PrepareBatch and 0.14s in
DMSIterator::MayHaveDeltas. So, about 46% of our time here is on wasted work.
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