openGauss每日一练第19天 | 学习心得体会
补之前的作业。今天(2021年12月26日)朋友推荐我看这个教程。
一下午都在做这个作业，每行代码都通过墨天轮的平台验证过了。
做完作业有个考试，91分通过。
总体感觉这个课程还是很不错的，一共21天，下面是第19天的作业内容。
19.1 openGauss收集统计信息、打印执行计划、垃圾收集和checkpoint
课后作业
1.创建分区表，并用generate_series(1,N)函数对表插入数据
Create schema tpcds;
CREATE TABLE tpcds.customer_address
(
ca_address_sk integer NOT NULL ,
ca_address_id character(16),
ca_street_number character(10) ,
ca_street_name character varying(60) ,
ca_street_type character(15) ,
ca_suite_number character(10) ,
ca_city character varying(60) ,
ca_county character varying(30) ,
ca_state character(2) ,
ca_zip character(10) ,
ca_country character varying(20) ,
ca_gmt_offset numeric(5,2) ,
ca_location_type character(20)
);
insert into tpcds.customer_address values
(1, 'AAAAAAAABAAAAAAA', '18', 'Jackson', 'Parkway', 'Suite 280', 'Fairfield', 'Maricopa County', 'AZ', '86192' ,'United States', -7.00, 'condo'),
(2, 'AAAAAAAACAAAAAAA', '362', 'Washington 6th', 'RD', 'Suite 80', 'Fairview', 'Taos County', 'NM', '85709', 'United States', -7.00, 'condo'),
(3, 'AAAAAAAADAAAAAAA', '585', 'Dogwood Washington', 'Circle', 'Suite Q', 'Pleasant Valley', 'York County', 'PA', '12477', 'United States', -5.00, 'single family');
insert into tpcds.customer_address values(generate_series(10, 10000));
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2.收集表统计信息
select relname, relpages, reltuples from pg_class where relname = 'customer_address';
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3.显示简单查询的执行计划；建立索引并显示有索引条件的执行计划
EXPLAIN SELECT * FROM tpcds.customer_address;
create index customer_address_idx on tpcds.customer_address(ca_address_sk);
EXPLAIN SELECT * FROM tpcds.customer_address WHERE ca_address_sk<100;
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4.更新表数据，并做垃圾收集
update tpcds.customer_address set ca_address_sk = ca_address_sk + 1 where ca_address_sk <100;
VACUUM (VERBOSE, ANALYZE) tpcds.customer_address;
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5.清理数据
drop schema tpcds cascade;
=========================
