TableEnvironment. TableEnvironment is responsible for: • Table management: Table Creation, listing Tables, Conversion between Table and DataStream, etc. • User-defined function management: User-defined function registration +----+----------------------+--------------------------------+ 2 rows in set PyFlink Table also provides the conversion back to a pandas DataFrame to leverage pandas API. [14]: table.to_pandas() [14]: id data 0 1 'aaa|a')], type_info=Types.ROW([Types.INT(), Types.STRING()])) ds.get_type() [3]: RowTypeInfo(f0: Integer, f1: String) Create a DataStream from DataStream Connectors [4]: from pyflink.common.watermark_strategy

TableEnvironment. TableEnvironment is responsible for: • Table management: Table Creation, listing Tables, Conversion between Table and DataStream, etc. • User-defined function management: User-defined function registration +----+----------------------+--------------------------------+ 2 rows in set PyFlink Table also provides the conversion back to a pandas DataFrame to leverage pandas API. [14]: table.to_pandas() [14]: id data 0 1 'aaa|a')], type_info=Types.ROW([Types.INT(), Types.STRING()])) ds.get_type() [3]: RowTypeInfo(f0: Integer, f1: String) Create a DataStream from DataStream Connectors [4]: from pyflink.common.watermark_strategy

for it) • Flink has a built-in type system which supports: • basic types, i.e., String, Long, Integer, Boolean, Array • composite types: Tuples, POJOs, and Scala case classes • Kryo for unknown types ◦have a default getter and setter Tuple2Integer> person = new Tuple2<>("Fred", 35); // zero based index! String name = person.f0; Integer age = person.f1; public class Person { public String name; public Integer age; public Person() {}; public Person(String name, Integer age) { … }; } Person person = new Person("Fred Flintstone"

select a stream element i with probability 10%. • We can use a random generator that produces an integer ri between 0 and 9. We then select an input element i if ri=0. 8 Q: How many queries did users select a stream element i with probability 10%. • We can use a random generator that produces an integer ri between 0 and 9. We then select an input element i if ri=0. 8 Will this approach provide the user is sampled: add the query to S • if we haven’t seen the user before: generate a random integer ru between 0 and 9 and add the user to the sample if ru = 0. ??? Vasiliki Kalavri | Boston University