[
https://issues.apache.org/jira/browse/IOTDB-1158?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17292267#comment-17292267
]
sunjincheng commented on IOTDB-1158:
------------------------------------
Reopen this issue, I'd like to listen to more thoughts, such as the treatment
of non numerical types.
> Add nullable support for any datatype
> -------------------------------------
>
> Key: IOTDB-1158
> URL: https://issues.apache.org/jira/browse/IOTDB-1158
> Project: Apache IoTDB
> Issue Type: New Feature
> Components: Core/Engine
> Reporter: sunjincheng
> Assignee: sunjincheng
> Priority: Major
> Attachments: image-2021-02-17-08-58-46-610.png, screenshot-1.png
>
>
> DDL of many databases can support not null syntax, such as MySQL [1]:
> {code:java}
> CREATE TABLE order (
> item VARCHAR(255) NOT NULL,
> amount FLOAT NOT NULL,
> deal_date DATE
> );
> {code}
> A column may contain only one `NOT NULL` constraint which specifies a rule
> that the column must not contain any `NULL` value. In other words, by
> default, `NULL` value is allowed.
> For performance reasons, IoTDB does not support `NULL` value by default.
> Instead, it supports some business scenarios in the form of 'NaN'. As shown
> in the figure below:(v0.11.2)
> !image-2021-02-17-08-58-46-610.png!
> Therefore, in this JIRA., we will discuss whether we need to support `NULL`
> value and how to support `NULL` values in IoTDB, including session API and
> SQL API. I'd like to provide a draft of how to support the design, if you
> think this feature is necessary.
> What are your thoughts?
> [1] [https://www.mysqltutorial.org/mysql-not-null-constraint/]
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
