Sexy Girls And Management

 Database Modeling Building Blocks

Other than all these wonderful indexing things, there are further possiblities within relational databases that some database engines allow and some do not. It is important to know that specialized objects exist as options for expansion to a relationsl database model, as extensions to both the underlying physical structure of a database and the overlying logical structure (the tables and indexes). Following are a few examples:

Views --- a view is essentially a query definition and does not contain any data. A view is not a phyusical copyu of data and does not contain any data itself. A view is merely a logical overlay of existing tables. Every execution against a view executes the query contained within view against all rnderlying tables. The danger with using views is filtering a query against a view, expecting to read a very small portion of a very large table.. any filtering should be done within the view because any filtering against the view itself is applied after the query in the view has complited execution. Views are typically useful for speeding up the developoment process but in the long run can completely kill database performance.