Hello Kudu Jenkins,
I'd like you to reexamine a change. Please visit
http://gerrit.cloudera.org:8080/6623
to look at the new patch set (#4).
Change subject: Allow to pad UNIXTIME_MICROS slots in scan results
......................................................................
Allow to pad UNIXTIME_MICROS slots in scan results
This changes the wire protocol to, upon request, pad
the slots that contain values for UNIXTIME_MICROS columns
by 8 bytes. This allows Impala to adopt the result of a
Kudu scan as a whole while still having space to transform
UNIXTIME_MICROS values, which occupy 8 bytes, to the Impala
representation of timestamp, which occupies 16, in place
and without copying memory.
This patch doesn't include any de-serialization logic
the reasoning being that Impala will have knowledge of
the data format in order to perform de-serialization
directly on the "raw" direct and indirect data.
This patch doesn't introduce any branching in the
serialization patch. It does move the memset() call
that was performed once per nullable column, per row,
to be performed on the whole block instead. While less
cache friendly, this is also executed less times. The
net gain is not significant, but it does not regress
in the normal case.
Results of running the wire_protocol-test benchmark
in slow mode:
Before (avg 3 runs): 3.076
After (avg 3 runs): 3.000
The difference is around -2%, which might be in the noise
but demostrates no significant regression.
Change-Id: I99fc6d3be089d19ebe2e70c938f2405c381578b4
---
M src/kudu/common/wire_protocol-test.cc
M src/kudu/common/wire_protocol.cc
M src/kudu/common/wire_protocol.h
3 files changed, 134 insertions(+), 21 deletions(-)
git pull ssh://gerrit.cloudera.org:29418/kudu refs/changes/23/6623/4
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Gerrit-MessageType: newpatchset
Gerrit-Change-Id: I99fc6d3be089d19ebe2e70c938f2405c381578b4
Gerrit-PatchSet: 4
Gerrit-Project: kudu
Gerrit-Branch: master
Gerrit-Owner: David Ribeiro Alves <dral...@apache.org>
Gerrit-Reviewer: Jean-Daniel Cryans <jdcry...@apache.org>
Gerrit-Reviewer: Kudu Jenkins
Gerrit-Reviewer: Matthew Jacobs <m...@cloudera.com>
Gerrit-Reviewer: Tidy Bot
Gerrit-Reviewer: Todd Lipcon <t...@apache.org>
