SparkSQL: What is the cost of DataFrame.registerTempTable(String)? Can I have multiple tables referencing to the same DataFrame?

[Anfernee Xu]

Hi,

I just want to understand the cost of DataFrame.registerTempTable(String),
is it just a trivial operation(like creating a object reference) in
master(Driver) JVM? And Can I have multiple tables with different name
referencing to the same DataFrame?

Thanks

-- 
--Anfernee