The CData Cmdlets PowerShell Module for HDFS supports standard SQL joins like the following examples.

Inner Join

An inner join selects only rows from both tables that match the join condition:

SELECT c.Owner, o.OwnerRead, o.OwnerWrite, o.OwnerExecute FROM Files c INNER JOIN Permissions o ON c.FullPath = o.FullPath

Left Join

A left join selects all rows in the FROM table and only matching rows in the JOIN table:

 SELECT c.Group, o.GroupRead, o.GroupWrite, o.GroupExecute FROM Files c LEFT JOIN Permissions o ON c.FullPath = o.FullPath