bubaxiu的专栏

如何看懂ORACLE执行计划一、什么是执行计划An explain plan is a representation of the access path that is taken when a query is executed within Oracle.二、如何访问数据At the physical level Oracle reads blocks of data.

select user_cons_columns.constraint_name as 约束名,         user_cons_columns.table_name      as 子表名,         user_cons_columns.column_name     as 子表列名,         user_cons_columns.position        as