Databases, tablespaces, and datafiles are closely related, but they have important differences:An Oracle database consists of one or more logical storage units called tablespaces, which collectively store all of the database's data.Each tablespace in an Oracle database consists of one o...【阅读全文】
1、查一下这些视图的定义你就能理解,它们的源都是一个。 SELECT view_definition FROM v$fixed_view_definition WHERE view_name='GV$SQL'; SELECT view_definition FROM v$fixed_view_definition WHERE view_name='GV$SQL_AREA'; 2、实际上最模糊的是v$sql与v$sqlarea,区别与联系除biti说的还有: ...【阅读全文】
有时候对表进行了大量的更新操作或者在表中增加了一列含有默认值的列,那么就有可能出现表的行迁移情况,这种情况造成了对数据访问的过多的逻辑读HR@orcl>create table employee_test as select * from employees;表已创建。HR@orcl>desc employee_test名称 ...【阅读全文】