JMap Server System Database

JMap Server’s System database is a relational database that stores important data for JMap Server. User account and group data is stored in this database if you are using JMap Server’s built-in user manager. This is not the case if you are using another user manager (e.g.: LDAP/Active Directory). Also, when spatial data sources read their data from files (SHP, MIF, DWG, etc.), the geometry and descriptive data read from the files are inserted in tables of the System database. There is one data table per such data source, as well as spatial index tables that speed up data extraction. Personal layers created by the users as well as JMap Spatial tables are also stored in the System database.

The relational database management system (RDBMS) used by default for storing JMap Server’s System databases is Apache Derby. It is embedded in JMap Server and requires no maintenance. This system is suitable for publishing small spatial data volumes or for test environments. It is strongly recommended to use another relational database management system. The list of compatible systems is presented in the article Technical Specifications of JMap Server Kathmandu from the JMap Knowledge Base. By default, Derby’s database files are located under the directory JMAP_HOME/db/database. Never delete or alter any file located in this directory.

Moving the JMap Server System database to another environment

JMap Server’s System database can be moved to another RDBMS easily. It is recommended to do it for scalability or performance reasons or to take advantage of more advanced features such as backups. The officially supported RDBMS for storing the JMap System database are detailed in the article Technical Specifications of JMap Server Kathmandu from the JMap Knowledge Base.

Note that other RDBMS and versions will also probably be supported because JMap Server uses mostly very common and simple database functions.

To store the System database, you should use a database or schema that is reserved exclusively for JMap. The user account that established the connection must have sufficient privileges to select, insert, create, and delete tables and indexes.

To move the System database towards another RDBMS, you must modify the database called System in JMap Admin. Select the database driver and connection parameters associated with the environment of the new System database. JMap Server will automatically create the required tables in the new database.

After the System database is moved, any spatial data source that reads vector data files will have a Not ready status. It will need to be updated before it can be used. Other types of data sources (raster, Oracle Spatial, SDE, etc.) will not be affected.

In addition, if you move the System database, all user data from the previous database must be moved using the data import and export tool. For more information, see the Exporting and Importing section.