44 lines
1.5 KiB
HTML
44 lines
1.5 KiB
HTML
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<TITLE>The POSTGRES95 User Manual - THE POSTGRES RULE SYSTEM</TITLE>
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<font size=-1>
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<A HREF="pg95user.html">[ TOC ]</A>
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<A HREF="lobj.html">[ Previous ]</A>
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<A HREF="admin.html">[ Next ]</A>
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<H1>14. THE POSTGRES RULE SYSTEM
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</H1><HR>
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Production rule systems are conceptually simple, but
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there are many subtle points involved in actually using
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them. Consequently, we will not attempt to explain the
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actual syntax and operation of the POSTGRES rule system
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here. Instead, you should read <A HREF="refs.html#STON90b">[STON90b]</A> to understand
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some of these points and the theoretical foundations of
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the POSTGRES rule system before trying to use rules.
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The discussion in this section is intended to provide
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an overview of the POSTGRES rule system and point the
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user at helpful references and examples.
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The "query rewrite" rule system modifies queries to
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take rules into consideration, and then passes the modified
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query to the query optimizer for execution. It
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is very powerful, and can be used for many things such
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as query language procedures, views, and versions. The
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power of this rule system is discussed in
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<A HREF="refs.html#ONG90">[ONG90]</A> as
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well as <A HREF="refs.html#STON90b">[STON90b]</A>.
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<HR>
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<font size=-1>
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<A HREF="pg95user.html">[ TOC ]</A>
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<A HREF="lobj.html">[ Previous ]</A>
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<A HREF="admin.html">[ Next ]</A>
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</font>
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