课程作业

1.创建表，创建普通视图

omm=# Create schema tpcds;
CREATE SCHEMA
omm=# CREATE TABLE tpcds.customer
omm-# (  c_customer_sk             integer,   
omm(#   c_customer_id             char(5),    
omm(#   c_first_name              char(6),    
omm(#   c_last_name               char(8) 
) ;
omm(# CREATE TABLE
omm=# omm-# INSERT INTO tpcds.customer VALUES    
omm-# (6885, 1, 'Joes', 'Hunter'),    
(4321, 2, 'Lily','Carter'),    
omm-# (9527, 3, 'James', 'Cook'),
omm-# (9500, 4, 'Lucy', 'Baker');
INSERT 0 4

omm=# CREATE VIEW tpcds.customer_details_view_v1 AS
omm-# SELECT * FROM tpcds.customer
omm-# WHERE c_customer_sk > 5400;
CREATE VIEW

omm=# select * from tpcds.customer_details_view_v1;

          9527 | 3             | James        | Cook    
          9500 | 4             | Lucy         | Baker   
(3 rows)

omm=#  c_customer_sk | c_customer_id | c_first_name | c_last_name 
---------------+---------------+--------------+-------------
          6885 | 1             | Joes         | Hunter  
omm=# 
复制

2.使用视图创建新的视图

omm=# create  VIEW tpcds.part_view as  SELECT * FROM  tpcds.customer_details_view_v1 where  c_customer_sk =9527;
CREATE VIEW
omm=#  --查看新的视图
omm=# select * from tpcds.part_view;
 c_customer_sk | c_customer_id | c_first_name | c_last_name 
---------------+---------------+--------------+-------------
          9527 | 3             | James        | Cook    
(1 row)

omm=# 
复制

3.创建物化视图

omm=# drop materialized view if exists mv_test;
NOTICE:  materialized view "mv_test" does not exist, skipping
DROP MATERIALIZED VIEW
omm=# drop table if exists test;
NOTICE:  table "test" does not exist, skipping
DROP TABLE
omm=# create table test(id serial primary key,testnum serial);
NOTICE:  CREATE TABLE will create implicit sequence "test_testnum_seq" for serial column "test.testnum"
NOTICE:  CREATE TABLE will create implicit sequence "test_id_seq" for serial column "test.id"
NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "test_pkey" for table "test"
CREATE TABLE
omm=# insert into test(testnum) values(generate_series(1,100000));
INSERT 0 100000
omm=# 
omm=# --创建物化视图：
omm=# create materialized view mv_test as 
omm-# select * from test where testnum%2=0;
CREATE MATERIALIZED VIEW
omm=# 
omm=# --查看物化视图目前有多少行记录：
omm=# select count(*) from mv_test;
omm=#  count 
-------
 50000
(1 row)

omm=# 

复制

4.手动更新物化视图

omm=# 
insert into test(testnum) values(generate_series(1,100000));
INSERT 0 100000
omm=# select count(*) from mv_test;
 count 
-------
 50000
(1 row)

omm=# 
omm=# --手动更新物化视图，并查看更新物化视图后，物化视图有多少行记录：
omm=#   refresh materialized view mv_test;
REFRESH MATERIALIZED VIEW
omm=#  select count(*) from mv_test;
 count  
--------
 100000
(1 row)
复制

5.删除创建的视图

omm=# DROP view tpcds.part_view;
DROP VIEW
omm=# DROP view TPCDS.customer_details_view_v1;
DROP VIEW
omm=# 
omm=# --删除物化视图
omm=# DROP MATERIALIZED VIEW mv_test;
DROP MATERIALIZED VIEW
复制