Specifies the file that contains a description of the database schema to which the beans in this sun-cmp-mappings.xml file are mapped. If this element is empty, the database schema file is automatically generated at deployment time. Otherwise, the schema element names a .dbschema file with a pathname relative to the directory containing the sun-cmp-mappings.xml file, but without the .dbschema extension. See Automatic Database Schema Capture in Oracle GlassFish Server 3.1 Application Development Guide.
none - contains data
<schema/> <!-- use automatic schema generation -->
<schema>CompanySchema</schema> <!-- use "CompanySchema.dbschema" -->