What is a database meta-schema? (4db)
A database meta-schema file is the central repository of a database's meta-data, containing information about the tables, columns, and relations, and default values of a relational database. Information from the database meta-schema file is used by Genero Studio Report Designer, Business Application Modeling, and Code Editor.
4db files
There is one type of database meta-schema files used by Genero Report Writer. The .4db database meta-schema file is used in all projects, regardless of whether the applications are generated using the Business Application Modeler.
The database meta-schema file includes information that is not found in the database itself, such as predefined labels and default display values.
When is it used?
- Examine the structure of a tables, columns, and other attributes.
- Generate application code.
The database meta-schema is not used by Genero Studio when an application is executed. Genero Studio uses the Genero runtime system and the specific database client software to access any databases referenced in a Genero application.
Meta-schema creation and maintenance
Database meta data can be extracted from a relational database into a meta-schema file, or it can be based on an existing database schema file.
It is important that the database meta-schema file match the current structure of the database itself. If changes are made in the database structure, any database meta-schema files that describe the database must also be updated.
GSTSCHEMANAMES
Set the GSTSCHEMANAMES environment variable to make meta-schemas available to all projects.