Internal Jenkins has submitted this change and it was merged.

Change subject: IMPALA-3163: Fix Decimal to Timestamp casting
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IMPALA-3163: Fix Decimal to Timestamp casting

Before this patch, we would first convert the Decimal to Double, then
Double to Timestamp. This resulted in imprecise results.

I ran a benchmark where we read decimal values from a large parquet
table and cast them to timestamp. The new correct implementation is
slightly slower than the old one (101 seconds vs 70 seconds).

Change-Id: Iabeea9f4ab4880b2f814408add63c77916e2dba9
Reviewed-on: http://gerrit.cloudera.org:8080/3154
Reviewed-by: Dan Hecht <[email protected]>
Tested-by: Internal Jenkins
---
M be/src/exprs/decimal-operators-ir.cc
M be/src/exprs/decimal-operators.h
M be/src/exprs/expr-test.cc
3 files changed, 75 insertions(+), 7 deletions(-)

Approvals:
  Internal Jenkins: Verified
  Dan Hecht: Looks good to me, approved



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Gerrit-MessageType: merged
Gerrit-Change-Id: Iabeea9f4ab4880b2f814408add63c77916e2dba9
Gerrit-PatchSet: 8
Gerrit-Project: Impala
Gerrit-Branch: cdh5-2.6.0_5.8.0
Gerrit-Owner: Taras Bobrovytsky <[email protected]>
Gerrit-Reviewer: Dan Hecht <[email protected]>
Gerrit-Reviewer: Internal Jenkins
Gerrit-Reviewer: Taras Bobrovytsky <[email protected]>

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