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This article mainly shows you "how to achieve a partition table in Hive", the content is easy to understand, clear, hope to help you solve your doubts, the following let the editor lead you to study and learn "how to achieve partition table in Hive" this article.

Partition table

For a larger table, designing it as a partition table can improve the performance of the query. For a query with a specific partition, only the file data of the corresponding partition path will be loaded. Therefore, when a user executes a select query with a specific partition column value, the query will only be executed for that particular partition, which can provide better performance because it will be scanned for a smaller amount of data. It is worth noting that the selection of partition fields is an important factor affecting query performance, and try to avoid deep-level partitions, which will result in too many subfolders.

Now the question is, which columns should be used for partitioning? A basic rule is to select a low cardinality attribute as the "partition key", such as "region" or "date".

Some common partition fields can be:

Date or time

Such as year, month, day, or hour, which can be used when there are time or date fields in the table.

Geographical location

Such as countries, provinces, cities, etc.

Business logic

Such as department, sales area, customer, etc.

CREATE TABLE table_name (

Col1 data_type

Col2 data_type)

PARTITIONED BY (partition1 data_type, partition2 data_type, … ); these are all the contents of the article "how to implement Partition tables in 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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