spark createOrReplaceTempView vs createGlobalTempView

Question

Spark Dataset 2.0 provides two functions createOrReplaceTempView and createGlobalTempView. I am not able to understand the basic difference between both functions.

According to API documents:

createOrReplaceTempView: The lifetime of this temporary view is tied to the [[SparkSession]] that was used to create this Dataset.
So, when I call sparkSession.close() the defined will be destroyed. is it true?

createGlobalTempView: The lifetime of this temporary view is tied to this Spark application.

when this type of view will be destroyed? any example. like sparkSession.close()?

Answer 1

df.createOrReplaceTempView("tempViewName")
df.createGlobalTempView("tempViewName")

createOrReplaceTempView() creates or replaces a local temporary view with this dataframe df. Lifetime of this view is dependent to SparkSession class, is you want to drop this view :

spark.catalog.dropTempView("tempViewName")

or stop() will shutdown the session

self.ss = SparkSession(sc)
...
self.ss.stop()

createGlobalTempView() creates a global temporary view with this dataframe df. life time of this view is dependent to spark application itself. If you want to drop :

spark.catalog.dropGlobalTempView("tempViewName")

or stop() will shutdown

ss =  SparkContext(conf=conf, ......)
...
ss.stop()