在视图及其基础表上运行查询之间的区别

Question

Is there a difference, in performance or otherwise, between running a query over a view or there underlying tables.

There may be aggregations, sorting involved in the query.

Any resources where this subject is dealt is welcome.

Answer 1

Ideally a View is just a projection on the underlying tables with optional criteria, generally used to hide certain columns or simplify the complexity involved in joining multiple tables to achieve a particular task etc., and wouldn't have any physical existence in the database. So, a query that is run on the view and a query same as the previous one run on the underlying tables perform in the same way.