When to use Join vs Append

[echenty]

Hello!

I feel like this is a simple answer and I kind of feel like I know the nuances between when to use the tool. I'm finding it hard to articulate in which use cases one is better than the other. Can anyone think of when would best to use append instead of join?

Thanks!

Emily

[MarqueeCrew]

When you have a set of constant values to add to all records, use the append function. 

[tsturge]

- Use the join when you have multiple fields to join on

- Append tools only do Cartesian joins, essentially a blind join between two data sets.  You can wikipedia Cartesian join for deeper explanation

- I believe there is an record limit on the source side input of an append tool because it can explode your data set and crash your module very quickly if done wrong

For every 1000 joins tools I have used I might use 1 append tool.  If you don't have a common key between your data sets then Append tool will work.