openGauss每日一练第19天 | 学习心得体会

一些运维工作

收集统计信息、打印执行计划、垃圾收集和checkpoint

--准备数据--
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));

select relname, relpages, reltuples from pg_class where relname = 'customer_address';

analyze VERBOSE tpcds.customer_address;
SET explain_perf_mode=normal;
EXPLAIN SELECT * FROM tpcds.customer_address;
EXPLAIN(FORMAT JSON) SELECT * FROM tpcds.customer_address;EXPLAIN SELECT SUM(ca_address_sk) FROM tpcds.customer_address WHERE ca_address_sk<100;

EXPLAIN(COSTS FALSE)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;
update tpcds.customer_address set ca_address_sk = ca_address_sk + 1 where ca_address_sk <100;
VACUUM (VERBOSE, ANALYZE) tpcds.customer_address;

CHECKPOINT;
drop schema tpcds cascade;

2.作业

CREATE TABLE A(id int)
PARTITION BY RANGE(id)
( partition a0 values less than (100),
partition a1 values less than (500));
INSERT INTO A VALUES(generate_series(1,499));

analyze VERBOSE A;
select relname, relpages, reltuples from pg_class where relname = 'a';

explain select * from A;

CREATE INDEX id_1 ON A(id);
explain select * from A where id = 1;
DELETE FROM A WHERE id < 3;
VACUUM(VERBOSE) A;