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<a accesskey="1" href="page.php?w=database_schema&amp;p=1">1.Previous</a><br />
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<p>The formal definition of a <a href="page.php?w=database">database</a> schema is a set of formulas (sentences) called <a href="page.php?w=integrity_constraints">integrity constraints</a> imposed on a database. These integrity constraints ensure compatibility between parts of the schema. All constraints are expressible in the same language. A database can be considered a structure in realization of the <a href="page.php?w=database_language">database language</a>. The states of a created <a href="page.php?w=conceptual_schema">conceptual schema</a> are</p><p>
<a accesskey="1" href="page.php?w=database_schema&amp;p=1">1.Previous</a><br />
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