You are viewing a plain text version of this content. The canonical link for it is here.
Posted to issues@arrow.apache.org by "ASF GitHub Bot (JIRA)" <ji...@apache.org> on 2018/02/07 19:19:00 UTC
[jira] [Commented] (ARROW-1942) [C++] Hash table specializations
for small integers
[ https://issues.apache.org/jira/browse/ARROW-1942?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16355914#comment-16355914 ]
ASF GitHub Bot commented on ARROW-1942:
---------------------------------------
xuepanchen commented on a change in pull request #1551: ARROW-1942: [C++] Hash table specializations for small integers
URL: https://github.com/apache/arrow/pull/1551#discussion_r166725654
##########
File path: cpp/src/arrow/compute/kernels/util-internal.h
##########
@@ -47,11 +52,11 @@ using enable_if_timestamp =
typename std::enable_if<std::is_base_of<TimestampType, T>::value>::type;
template <typename T>
-using enable_if_has_c_type =
- typename std::enable_if<std::is_base_of<PrimitiveCType, T>::value ||
- std::is_base_of<DateType, T>::value ||
- std::is_base_of<TimeType, T>::value ||
- std::is_base_of<TimestampType, T>::value>::type;
+using enable_if_has_c_type = typename std::enable_if<
+ !std::is_same<UInt8Type, T>::value && !std::is_same<Int8Type, T>::value &&
Review comment:
I am not sure how to exclude 8-bit integers in the functor declarations. I am thinking creating a new template function like "enable_if_has_c_type_excluding_8bit_integer" here and use it in the declaration of hash table pass for primitive types
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
> [C++] Hash table specializations for small integers
> ---------------------------------------------------
>
> Key: ARROW-1942
> URL: https://issues.apache.org/jira/browse/ARROW-1942
> Project: Apache Arrow
> Issue Type: Improvement
> Components: C++
> Reporter: Wes McKinney
> Assignee: Panchen Xue
> Priority: Major
> Labels: pull-request-available
> Fix For: 0.9.0
>
>
> There is no need to use a dynamically-sized hash table with uint8, int8, since a fixed-size lookup table can be used and avoid hashing altogether
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)