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Posted to dev@iotdb.apache.org by "Haonan Hou (Jira)" <ji...@apache.org> on 2020/03/03 08:24:00 UTC
[jira] [Commented] (IOTDB-430) using star to get records count is
poor efficiency than using integer
[ https://issues.apache.org/jira/browse/IOTDB-430?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17049994#comment-17049994 ]
Haonan Hou commented on IOTDB-430:
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Hi, I tried to use count(1) in 0.10.0, but I don't think there are enough reasons to support select count(1).
First, IoTDB is able to use integer number as path node, like root.1.1. The definition of select count(1) could be counting sensor 1 from root.
Second, I don't think select count(*) is poor efficiency than select count(1). It may be more efficiency in relational database, I'm not sure. But IoTDB is not using the same counting strategy. We cannot compare the efficiency like relational database.
> using star to get records count is poor efficiency than using integer
> ---------------------------------------------------------------------
>
> Key: IOTDB-430
> URL: https://issues.apache.org/jira/browse/IOTDB-430
> Project: Apache IoTDB
> Issue Type: Improvement
> Reporter: lming
> Priority: Major
>
> when I want to get records count in postgresql and other relational database , I will using form of count(1) for high efficiency than count(*)
> But in release 0.9.0 I only could get count by star .
> select count(*) is poor efficiency than select count(1)
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