Tips and Troubleshooting for Joins

The sections below provide tips and troubleshooting information for joins.

Joins that do not require record caches
There are two join cases that do not require record caches:
Working with sources that have multiple records with the same join key value
In order to configure a join with the desired behavior, it is important to have a strong understanding of what happens when record assemblers process records that do not have unique values for their join keys (higher cardinality joins).
Best practice for choosing left and right side of joins
A best practice is to keep record sources with the most values per join key on the left side of joins.
Combining equivalent records in record caches
The General tab on the Record Cache editor has a Combine Records setting. With the setting enabled for record caches, equivalent records in data sources are combined.
Forge warnings when combining large numbers of records
When combining a large number of records (via either a Combine join or a record cache with the Combine Records setting enabled), Forge will issue a warning that performance may be slow. The default number of records at which this warning is issued is 100.