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From "Tianyi Wang (Code Review)" <>
Subject [Impala-ASF-CR] IMPALA-5573: Add decimal codegen in text scanner
Date Wed, 23 Aug 2017 00:16:14 GMT
Hello Impala Public Jenkins, Tim Armstrong,

I'd like you to reexamine a change.  Please visit

to look at the new patch set (#9).

Change subject: IMPALA-5573: Add decimal codegen in text scanner

IMPALA-5573: Add decimal codegen in text scanner

This patch adds decimal type codegen support in text scanner. Currently
codegen would be disabled if there is a decimal column. With this patch
StringParser::StringToDecimal will be called in generated code. A new
file util/ is created and linked into libUtil. This file
contains proxy functions to StringToDecimal in ordered to keep
StringToDecimal out of LLVM IR.

In a benchmark query:
> select l_quantity, l_extendedprice, l_discount, l_tax from biglineitem where l_quantity
> 100.0;
where biglineitem is tpch.lineitem repeated 6 times, the codegen version
is 19% faster than non-codgen version in scanning, and 8% faster in
query time. Codegen time in this simple case is 69ms.

Simple performance tests show that putting the parser in libUtil instead
of impala-sse.bc would reduce codegen time by 2/3 in cases where only
one decimal column is parsed while the scanning time is nearly the same.

Change-Id: Ia65820e969d59094dc92d912a5279fa90f6b179d
M be/src/codegen/
M be/src/exec/
M be/src/exec/
M be/src/exec/
M be/src/util/CMakeLists.txt
M be/src/util/
A be/src/util/
M be/src/util/string-parser.h
8 files changed, 137 insertions(+), 28 deletions(-)

  git pull ssh:// refs/changes/83/7683/9
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Gerrit-MessageType: newpatchset
Gerrit-Change-Id: Ia65820e969d59094dc92d912a5279fa90f6b179d
Gerrit-PatchSet: 9
Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-Owner: Tianyi Wang <>
Gerrit-Reviewer: Impala Public Jenkins
Gerrit-Reviewer: Tianyi Wang <>
Gerrit-Reviewer: Tim Armstrong <>

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