Data Warehousing Considerations (245)

Some data warehouses drop indexes on tables at night to facilitate faster loads.
However, all views dependent on the table whose index is dropped get invalidated.
This means that subsequently running any package that reference these dropped
views will invalidate the package.
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.
To make the view valid again, use one of the following statements:
SELECT * FROM vtest;
or
ALTER VIEW vtest compile;

資料倉儲系統中的依賴性問題
1. 有些資料倉儲系統會在夜間刪除表的索引以便加快資料載入速度。但是，所有依賴於被刪除索引的表的檢視將被置為無效狀態。
而引用了這些檢視的包在執行時也將被置於無效狀態。

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