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Editor to share with you what the data model of hive, I believe that most people do not know much, so share this article for your reference, I hope you can learn a lot after reading this article, let's go to understand it!

View (View)

A view is a virtual table and a logical concept; it can span multiple tables.

The view is based on the existing tables, and the view is based on the established tables.

Views can simplify complex queries.

Eg. Create view empinfo as select * from emp efocus dept d where e.deptno = d.deptno

Select * from empinfo

Bucket table (Bucket Table)

Bucket tables hash the data and store them in different files.

Create table bucket_table (sid int,sname string,age int) clustered by (sname) into 5 buckets

External table (External Table)

To point to data that already exists in HDFS, you can create a Partition

It is the same as the internal table in the organization of metadata, but the storage of actual data is quite different.

External tables have only one process, loading data and creating tables are completed at the same time, and do not move to the data warehouse, but just establish a link with external data. When you delete an external table, only the link is deleted.

Internal table

Similar in concept to Table in the database

Each Table has a corresponding directory to store data in the Hive

All Table data (excluding External Table) is stored in this directory

When you delete a table, both metadata and data are deleted

Partition table (Parttion)

Partition corresponds to the dense index of the Parttion column of the database

In Hive, a Parttion in a table corresponds to a directory under the table, and all Parttion data is stored in the corresponding directory.

These are all the contents of the article "what are the data models of hive?" Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!

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