View (SQL): Difference between revisions

Revision as of 14:34, 3 January 2007

Revision as of 11:53, 4 January 2007

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== Equivalency ==

A view is equivalent to its source query. When queries are run against views, the query is modified. IeFor example, if there exists a view named Accounts_view and the content is

<pre>

accounts view:

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FROM table_customers c JOIN accounts_table a

ON a.customerid = c.customer_id )</pre>

From this point on the optimiser takes the query, removes unnecessary complexity (Iei.e. it is not necessary to read the address, since the parent invocation doesedoes not make use of it) and then sends the query to the sqlSQL engine for processing.

==External links==