Hello Lars Volker, Tim Armstrong, Dan Hecht,
I'd like you to reexamine a change. Please visit
http://gerrit.cloudera.org:8080/7009
to look at the new patch set (#14).
Change subject: IMPALA-5315: Cast to timestamp fails for YYYY-M-D format
......................................................................
IMPALA-5315: Cast to timestamp fails for YYYY-M-D format
This change allows casting of a string in 'lazy' date/time
format to timestamp. The supported lazy date formats are:
yyyy-[M]M-[d]d
yyyy-[M]M-[d]d [H]H:[m]m:[s]s[.SSSSSSSSS]
[H]H:[m]m:[s]s[.SSSSSSSSS]
We will incur a SCAN performance penalty (approximately 1/2
TotalReadThroughput) when the string is in one of these
lazy date/time format.
Testing:
Benchmarked the performance consequence by executing this SQL on
a private build over 3.8 billion rows:
select min(cast (time_string as timestamp)) from private.impala_5315
Added tests for valid and invalid date/time format strings
in expr-test.cc to be inline with existing tests for CAST() function.
Change-Id: Ib9a184a09d7e7783f04d47588537612c2ecec28f
---
M be/src/exprs/expr-test.cc
M be/src/runtime/timestamp-parse-util.cc
M be/src/runtime/timestamp-parse-util.h
3 files changed, 224 insertions(+), 3 deletions(-)
git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/09/7009/14
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Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-MessageType: newpatchset
Gerrit-Change-Id: Ib9a184a09d7e7783f04d47588537612c2ecec28f
Gerrit-Change-Number: 7009
Gerrit-PatchSet: 14
Gerrit-Owner: Vincent Tran <[email protected]>
Gerrit-Reviewer: Dan Hecht <[email protected]>
Gerrit-Reviewer: Lars Volker <[email protected]>
Gerrit-Reviewer: Tim Armstrong <[email protected]>
Gerrit-Reviewer: Vincent Tran <[email protected]>
