openGauss 每日一练第 19 天打卡，我来了！又可以学习，真开心~

学习

今天第 19 课，学习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

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create schema lucifer;
create table lucifer.store
(
        id int,
        name CHAR(20)
)
partition by range (id)
(
        partition store_p0 values less than (50),
        partition store_p1 values less than (100),
        partition store_p2 values less than (150),
	partition store_p3 values less than (200),
        partition store_p4 values less than (10001)
);
insert into lucifer.store values(generate_series(10, 10000));

2.收集表统计信息

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select relname, relpages, reltuples from pg_class where relname = 'store';
analyze VERBOSE lucifer.store;
select relname, relpages, reltuples from pg_class where relname = 'store';

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

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SET explain_perf_mode=normal;
EXPLAIN SELECT * FROM lucifer.store;
create index store_idx on lucifer.store(id);
EXPLAIN SELECT * FROM lucifer.store WHERE id<100;

4.更新表数据，并做垃圾收集

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update lucifer.store set id = id + 1 where id < 100;
VACUUM (VERBOSE, ANALYZE) lucifer.store;

5.清理数据

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CHECKPOINT;
drop table lucifer.store;
drop schema lucifer;

写在最后

今天的作业打卡结束！🎉