select count(1) from ccc.table_a@ORCL111 where phone = fn_encryption('1888888888');
查询超级慢，接近30秒
select count(1) from ccc.table_a@ORCL111 where phone = '1888888888';
查询大概有3,4秒
直接在ORCL111里查询速度很快
select count(1) from table_a where phone = fn_encryption('1888888888');
原因不明，记录一下，待解决