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Toad Data Point 5.0 - User Guide

About Apache Hive Data Sources

Toad allows you to create a connection to and query a Hive data warehouse system. Apache Hive is one of the NoSQL data sources supported by Toad.

To learn how to create a new Hive connection, see Create Hive Connections.

Toad Automatically Maps Object Metadata

When you create a new connection to a Business Intelligence or NoSQL data source, Toad automatically maps the data source objects. Toad gathers metadata from these objects which is cached (in a hidden table) and retained between sessions. For Hive connections, this metadata is retained until manually refreshed.

During this initial mapping process, Toad maps only metadata. The actual data in each column is mapped as needed, such as when you execute a query.

Manually refresh object metadata

You can manually refresh object metadata at any time. In the Object Explorer, right-click an object and select Refresh All.

For Hive connections, you can right-click an object and select Refresh Schema to refresh only objects in that schema.

Considerations and Limitations

The following considerations and limitations apply when working with Hive data sources in Toad.

Consideration/Limitation Description
Object Explorer The Object Explorer displays the Hive Tables that were mapped by Toad, either when the connection was initially created or when the objects were refreshed.
Max character limit Toad maps up to 255 characters per VARCHAR data field.
Delay when executing query Hive columns and data are mapped as needed. Because of this, you may experience a delay when attempting to view columns and data or when executing a query.
Non-ANSI joins You cannot use non-ANSI join syntax in a Hive query.
INNER and OUTER joins You cannot use INNER JOIN or OUTER JOIN in a Hive query.
Use table aliases You must use table aliases and fully-qualified column names.
Alias names You cannot use table alias with the same name as the table or the column.
Read-only Hive connections are read-only. You cannot create tables using Toad. You cannot import data into a Hive data source from Toad.

  

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