temp_tab_name = "mytablename";
    x = spark.sql("select * from " +temp_tab_name +" limit 10");
    x = x.persist()
    x.count() #action to activate all the above steps
    x.show() #x should have been persisted in memory here, DAG evaluated, no going back to "select..." whenever referred to
    x.is_cached #True
    spark.sql("drop table "+ temp_tab_name);
    x.is_cached #Still true!!
    x.show() # Error, table not found here

# df method
df = spark.range(10)
df.count() # action to materialize df object in ram
df.unpersist() # remove df object from ram

# temp table method
df.createOrReplaceTempView("df_sql")
spark.catalog.cacheTable("df_sql")
spark.sql("select * from df_sql").count() # action to materialize temp table in ram
spark.catalog.uncacheTable("df_sql") # remove temp table from ram