>
> SO I tried the above (why doesn't union or ++ have the same behavior
> btw?)
I don't think there is a good reason for this. I'd open a JIRA.
> and it works, but is slow because the original Rdds are not
> cached and files must be read from disk.
>
> I also discovered you can recover the InMemoryCached versions of the
> Rdds using sqlContext.table("table1").
>
Yeah, this is an unfortunate consequence of the way we handle caching.
I've opened this JIRA for the 1.2 roadmap:
https://issues.apache.org/jira/browse/SPARK-3212
