1. Views

2. Learning Objectives
u Views
u Types of views

3. View
u Logical query against source tables
A1 A4 B2 B3
A1 A2 A3 A4 B1 B2 B3 B4
table_1 table_2
view_x
CREATE VIEW view_x
AS SELECT A1, A4, B2, B3
FROM table_1
INNER JOIN table_2 …

4. Types of views
1. (Stored) Views
2. Temporary views
3. Global Temporary views

5. 1- (Stored) Views
u Persisted objects
u CREATE VIEW view_name
AS query

6. 2- Temporary view
u Session-scoped view
u CREATE TEMP VIEW view_name
AS query

7. Spark Session
u Opening a new notebook
u Detaching and reattaching to a cluster
u Installing a python package
u Restarting a cluster

8. 3- Global Temporary views
u Cluster-scoped view
u CREATE GLOBAL TEMP VIEW view_name
AS query
u SELECT * FROM global_temp.view_name

9. Views comparison
(Stored) Views
u Persisted in DB
u Dropped only by
DROP VIEW
u CREATE VIEW
Global Temp views
u Cluster-scoped
u dropped when
cluster restarted
u CREATE GLOBAL
TEMP VIEW
Temp views
u Session-scoped
u dropped when
session ends
u CREATE TEMP VIEW