bitmap index

bitmap index

说明：

set echo on

drop table t purge;



create table t 

( processed_flag varchar2(1) 

);

create bitmap index

t_idx on t(processed_flag);

insert into t values ( 'N' );

declare

    pragma autonomous_transaction;

begin

    insert into t values ( 'N' );

    commit;

end;

/

 

如果数据在一个回话里执行会出现锁死错误，所以尽量不要用 bitmap index