64 lines
3.9 KiB
HTML
64 lines
3.9 KiB
HTML
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<?xml version="1.0" encoding="utf-8"?>
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
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"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US" xml:lang="en-us">
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
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<meta name="dc.language" scheme="rfc1766" content="en-us" />
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<!-- All rights reserved. Licensed Materials Property of IBM -->
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<!-- US Government Users Restricted Rights -->
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<!-- Use, duplication or disclosure restricted by -->
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<!-- GSA ADP Schedule Contract with IBM Corp. -->
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<meta name="dc.date" scheme="iso8601" content="2005-09-19" />
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<meta name="copyright" content="(C) Copyright IBM Corporation 1998, 2006" />
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<meta name="security" content="public" />
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<meta name="Robots" content="index,follow"/>
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<meta http-equiv="PICS-Label" content='(PICS-1.1 "http://www.icra.org/ratingsv02.html" l gen true r (cz 1 lz 1 nz 1 oz 1 vz 1) "http://www.rsac.org/ratingsv01.html" l gen true r (n 0 s 0 v 0 l 0) "http://www.classify.org/safesurf/" l gen true r (SS~~000 1))' />
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<meta name="keywords" content="description, collection (see schema), schema" />
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<title>Schemas</title>
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<link rel="stylesheet" type="text/css" href="ibmidwb.css" />
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<link rel="stylesheet" type="text/css" href="ic.css" />
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</head>
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<body>
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<a id="Top_Of_Page" name="Top_Of_Page"></a><!-- Java sync-link -->
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<script language = "Javascript" src = "../rzahg/synch.js" type="text/javascript"></script>
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<a name="collex"></a>
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<h2 id="collex"><a href="rbafzmst02.htm#ToC_26">Schemas</a></h2><a id="idx26" name="idx26"></a><a id="idx27" name="idx27"></a>
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<p>The objects in a relational database are organized into sets called schemas.
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A schema provides a logical classification of objects in a relational database.
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A <span class="italic">schema name</span> is used as the qualifier of SQL object
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names such as tables, views, indees, and triggers. A schema is also called
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a collection or library.</p>
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<p>Each database manager supports a set of schemas that are reserved for use
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by the database manager. Such schemas are called <var class="pv">system schemas</var>. User objects
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must not be created in <var class="pv">system schemas</var>, other than SESSION.</p>
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<p>The schema SESSION and all schemas that start with 'SYS' and 'Q' are <var class="pv">system schemas</var>. SESSION is always used as the schema name for declared
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temporary tables. Users should not create schemas that start with 'SYS' or
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'Q'.</p>
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<p>A schema is also an object in the relational database. It is explicitly
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created using the CREATE SCHEMA statement.<sup class="fn"><a id="wq6" name="wq6" href="rbafzmstcollex.htm#wq7">1</a></sup></p>
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<p>An object that is contained in a schema is assigned to the schema when
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the object is created. The schema to which it is assigned is determined by
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the name of the object if specifically qualified with a schema name or by
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the default schema name if not qualified.</p>
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<p>For example, a user creates a schema called C:</p>
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<pre class="xmp"> <span class="bold">CREATE SCHEMA</span> C </pre>
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<p>The user can then issue the following statement to create a table called
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X in schema C:</p>
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<pre class="xmp"> <span class="bold">CREATE TABLE</span> C.X (COL1 <span class="bold">INT</span>)</pre>
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<hr /><div class="fnnum"><a id="wq7" name="wq7" href="rbafzmstcollex.htm#wq6">1</a>.</div>
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<div class="fntext">A schema can also be created
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using the CRTLIB CL command, however, the catalog views and journal and journal
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receiver created by using the CREATE SCHEMA statement will not be created
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with CRTLIB.</div>
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<br />
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<hr /><br />
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[ <a href="#Top_Of_Page">Top of Page</a> | <a href="rbafzmstsqlcon.htm">Previous Page</a> | <a href="rbafzmstch1table.htm">Next Page</a> | <a href="rbafzmst02.htm#wq1">Contents</a> |
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<a href="rbafzmstindex.htm#index">Index</a> ]
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<a id="Bot_Of_Page" name="Bot_Of_Page"></a>
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</body>
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</html>
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