The CData SSIS Components for Splunk 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 DataModels.Name, Datasets.ObjectName FROM DataModels INNER JOIN Datasets ON DataModels.Id = Datasets.ModelName

Left Join

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

SELECT DataModels.Name, Datasets.ObjectName FROM DataModels LEFT JOIN Datasets ON DataModels.Id = Datasets.ModelName