#### Version resource structure in the server database

Information about versions, folders, nodes, the security system, the completed table, and server runtime performance are all stored in the default database HSQLDB. Also, since JReport Enterprise Server provides multiple database support, you can configure your own database to store server data. For production systems it is recommended to use the same DBMS as your database application so the server data will be backed up with the rest of the application.

This section discusses how version resources are stored in the server database - HSQLDB.

Generally, server data is stored in the folders `<install_root>\properties` and `<install_root>\profiling`, and version resources are stored in the systable.defaultRealm.* files in the properties folder.

To open the systable.defaultRealm.* files:

1. Use the following command to access the HSQLDB database manager:

   `%JAVAHOME%\bin\java -classpath <install_root>\lib\hsqldb.jar org.hsqldb.util.DatabaseManager`

2. In the Connect dialog, specify the connection information as follows:

   Type: HSQL Database Engine Standalone
   Driver: org.hsqldb.jdbcDriver
   URL: `jdbc:hsqldb:<install_root>\properties\systable.defaultRealm`
   (if you have another realm, you can also specify to check the server data in that realm)
   User: sa
   Password:

3. Click the OK button.
4. The HSQLDB database manager will then be displayed.

   In the left panel, you will see several tables that are used to store version information, such as VERSIONNODES_2, CATALOGVERSION_2, REPORTVERSION_2 and RESULTVERSION_2. In the HSQLDB database, you can execute commands to obtain data from these tables in order to see detailed version information.

   - Example 1: Finding result version information from the database

     Send the command `SELECT * FROM RESULTVERSION_2 WHERE CREATOR='admin'` to retrieve result versions which were created by the user 'admin'.

   - Example 2: Finding catalog version information from the database

     Execute the command `SELECT * FROM CATALOGVERSION_2` to fetch all catalog versions.

Note: Don't delete, update or insert data into the database. It is recommended that all modifications to the database be done from JReport Enterprise Server instead of in the HSQLDB DatabaseManager. Otherwise, it may result in JReport Enterprise Server crashing if invalid data is found.