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From "Tim Armstrong (Code Review)" <>
Subject [Impala-ASF-CR] IMPALA-5307: Part 2: copy out strings in uncompressed Avro
Date Tue, 24 Oct 2017 22:28:45 GMT
Tim Armstrong has posted comments on this change. ( )

Change subject: IMPALA-5307: Part 2: copy out strings in uncompressed Avro

Patch Set 11:

File be/src/runtime/tuple.h:
PS11, Line 289: );
> Are those calls to std C++ library functions ?
I realise now the comment didn't make sense without context. The invoke came from the call
to this function and was fixed by adding a "noexcept" specifier - we've used that in various
other places.
File be/src/runtime/
PS11, Line 449:   Value* result_val = builder.CreateCall(cross_compiled_fn,
> Yes. That seems to be helpful. Can we also do something bigger (e.g. 16 col
I did a quick microbenchmark and there is a ~10% difference in scan time between the codegen'd
and non-codegen'd when scanning a single string column.

Another case where it's useful is optimising out the loop and runtime checks entirely  when
no string cols are materialised.

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Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-MessageType: comment
Gerrit-Change-Id: If1fc78790d778c874f5aafa5958c3c045a88d233
Gerrit-Change-Number: 8146
Gerrit-PatchSet: 11
Gerrit-Owner: Tim Armstrong <>
Gerrit-Reviewer: Dan Hecht <>
Gerrit-Reviewer: Michael Ho <>
Gerrit-Reviewer: Thomas Tauber-Marshall <>
Gerrit-Reviewer: Tim Armstrong <>
Gerrit-Comment-Date: Tue, 24 Oct 2017 22:28:45 +0000
Gerrit-HasComments: Yes

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