Hello Kudu Jenkins,
I'd like you to reexamine a change. Please visit
http://gerrit.cloudera.org:8080/4164
to look at the new patch set (#6).
Change subject: Inlined dispatch for predicate evaluation
......................................................................
Inlined dispatch for predicate evaluation
In order to evaluate a predicate, the correct comparator given the
physical type of interest must first be determined. Currently, this
occurs once per batch when ColumnPredicate::Evaluate() is called. A
call to this will dispatch the comparator as a lambda to be applied in
a loop over all rows in the batch.
When decoder-level evaluation is enabled, rather than occuring in
batches, dispatch occurs for each cell, which leads to poorer
performance. To remediate this, the dispatch has been templatized in
hopes that the dispatching and branching are inlined.
This figure shows the performance of dictionary encoding for
decoder-level evaluation without this templating adjustment. The query
selects a single value out of a dictionary-encoded column containing
1M unique strings.
https://raw.githubusercontent.com/anjuwong/kudu/300f1e8bdf05bc16bdacacca22482e579e49de67/docs/images/SELECT_OUTSIDE_OF_RANGE_non_inlined.png
Compare the above with the plot below, which is the result of the same
query, but with inlined dispatch.
https://raw.githubusercontent.com/anjuwong/kudu/300f1e8bdf05bc16bdacacca22482e579e49de67/docs/images/SELECT_OUTSIDE_OF_RANGE_inlined.png
Change-Id: Iccfac9bc899362b442337050795b5ca8c4101268
---
M src/kudu/cfile/binary_plain_block.cc
M src/kudu/cfile/cfile_reader.cc
M src/kudu/common/column_predicate.cc
M src/kudu/common/column_predicate.h
4 files changed, 57 insertions(+), 41 deletions(-)
git pull ssh://gerrit.cloudera.org:29418/kudu refs/changes/64/4164/6
--
To view, visit http://gerrit.cloudera.org:8080/4164
To unsubscribe, visit http://gerrit.cloudera.org:8080/settings
Gerrit-MessageType: newpatchset
Gerrit-Change-Id: Iccfac9bc899362b442337050795b5ca8c4101268
Gerrit-PatchSet: 6
Gerrit-Project: kudu
Gerrit-Branch: master
Gerrit-Owner: Andrew Wong <andrew.w...@cloudera.com>
Gerrit-Reviewer: Alexey Serbin <aser...@cloudera.com>
Gerrit-Reviewer: Andrew Wong
Gerrit-Reviewer: Dan Burkert <d...@cloudera.com>
Gerrit-Reviewer: Kudu Jenkins
Gerrit-Reviewer: Todd Lipcon <t...@apache.org>
