刚看了一章oracle concepts的一章,对象间的依赖性。主要是依赖对象和引用对象的一些关系,某些引用对象变化后,直接或间接影响依赖其存在的对象的invlid,产生某些重编译。本地的依赖对象管理通过依赖关系表进行;远程的主要管理过程间的依赖关系,通过时间戳和特征标识。
关键点:
Oracle attempts to recompile an invalid object dynamically only if it has not been replaced since it was detected as invalid. This optimization eliminates unnecessary recompilations
Remember that whenever you create a table, index, and view, and then drop the index, all objects dependent on that table are invalidated, including views, packages, package bodies, functions, and procedures. This protects updatable join views
Because of how Oracle resolves references, it is possible for an object to depend on the nonexistence of other objects. This situation occurs when the dependent object uses a reference that would be interpreted differently were another object present
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