vacuum full t1;

【测试方法】

insert into t1 select generate_series(1,227);
postgres=# insert into t1 select generate_series(1,227);
INSERT 0 227
文件16KB
postgres=# select pg_relation_filepath('t1');
 pg_relation_filepath 
----------------------
 base/12418/49176
(1 row)
delete from t1;
vacuum FULL t1；

postgres=# select pg_relation_filepath ('t1');
base/12418/49182
重新生成文件，文件0KB

【代码流程】

 

 

 

 

 

 函数入口rebuild_relation

1）make_new_heap创建临时表

2）copy_heap_data

3）finsh_heap_swap

3.1）swap_relation_files

3.2）reindex_relation

3.3）performDeletion

3.4）RelationMapRemoveMapping

【调用栈】 

【参考】

https://zhuanlan.zhihu.com/p/367684089

标签：full,postgres,filepath,t1,relation,pg,vacuum,select
来源： https://www.cnblogs.com/jiangshifu/p/15314014.html