impala-reviews mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Zach Amsden (Code Review)" <ger...@cloudera.org>
Subject [Impala-ASF-CR] IMPALA-2020: Inline big number strings
Date Thu, 02 Mar 2017 21:03:48 GMT
Zach Amsden has posted comments on this change.

Change subject: IMPALA-2020: Inline big number strings
......................................................................


Patch Set 5:

(8 comments)

http://gerrit.cloudera.org:8080/#/c/5902/5//COMMIT_MSG
Commit Message:

PS5, Line 27: Query: select sum(cast(cast(l_extendedprice as double) as
            : decimal(14,2))) from tpch10_parquet.lineitem
            : Query submitted at: 2017-02-18 01:23:54 (Coordinator:
            : http://impala-dev:25000)
            : Query progress can be monitored at:
            : http://impala-dev:25000/query_plan?query_id=f0410a35e981a86b:e6d9207000000000
> elide
Done


PS5, Line 38: 0.83s
> error bars?
what do you mean exactly?


http://gerrit.cloudera.org:8080/#/c/5902/5/be/src/exprs/expr-value.h
File be/src/exprs/expr-value.h:

Line 177:             decimal4_val = +DecimalUtil::MAX_UNSCALED_DECIMAL4;
> Why do you want to convert it to an Rvalue? Just to avoid having to define 
I just defined it in the .cc - not doing so (and not converting to an rvalue) breaks the debug
build, but not the release build, as this does actually get inlined if defined in the header.


http://gerrit.cloudera.org:8080/#/c/5902/5/be/src/util/decimal-util.h
File be/src/util/decimal-util.h:

Line 57:   template<typename T>
> Describe what it does.
Done


PS5, Line 58: T
> Always is_integral?
Not necessarily, this would work for float / double as well.


PS5, Line 59: boost::
> static_assert is now part of the language, but I'm not sure if it works on 
I'll try it


Line 60:     return scale == 0 ? 1 : 10 * GetConstScaleMultiplier<T>(scale-1);
> Check for no overflow, if it can be done simply.
I think it can be done, not sure how simply.  Since this is constexpr, we are pretty constrained
in what we can use but I think another static assert could do it.


Line 136:   if (__builtin_const_p(scale) && p < 10) return GetConstScaleMultiplier<int32_t>(scale);
> Does this by itself speed anything up? If scale is constant at compile time
Let's remove it and find out.


-- 
To view, visit http://gerrit.cloudera.org:8080/5902
To unsubscribe, visit http://gerrit.cloudera.org:8080/settings

Gerrit-MessageType: comment
Gerrit-Change-Id: I5095a366d914cebb0b64bd434a08dbb55c90ed30
Gerrit-PatchSet: 5
Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-Owner: Zach Amsden <zamsden@cloudera.com>
Gerrit-Reviewer: Dan Hecht <dhecht@cloudera.com>
Gerrit-Reviewer: Jim Apple <jbapple-impala@apache.org>
Gerrit-Reviewer: Michael Ho
Gerrit-Reviewer: Zach Amsden <zamsden@cloudera.com>
Gerrit-HasComments: Yes

Mime
View raw message