Oracle内存表
alter table xxx storage(buffer_pool default);
将表从内存拿出

alter table xxx storage(buffer_pool keep);
将表放入内存

select count(无索引字段) from xxx，载入内存


select count(索引字段) from xxx，索引载入内存


alter system flush buffer_cache，暂时清空内存

SQL> select sum(bytes)/1024/1024 from dba_segments where buffer_pool='KEEP';

SQL> show parameter keep_cache;