The cross-region database is the recommended location for region startup and CICS resource definition files. This database can also be used for the deployment of program executables and BMS maps. You would typically deploy programs and maps to this location that are used by two or more regions.
A region database may be used for the deployment of program executables and BMS maps that are used specifically by that region. However, these files need to be deployed as part of cold-start processing so can have a detrimental affect on the time taken to start the region.
A custom database can be used for the deployment of program executables and BMS programs. Like the cross-region database, files in a custom database may be used by two or more regions. However, unlike the cross-region database, files can be categorised (e.g. region specific, staging levels, etc) by deploying them to different tables.
A data store is the most flexible of all of the types of database available for the deployment of programs and data files. A data store effectively provides a database hosted file system by allowing files to be categorised using a folder hierarchy. Each data file is represented by a table, whereas all other files such as programs and BMS maps are represented by blobs. Blobs are held within a single table.
Files can be transferred between a file system and any of the database locations above using either the Enterprise Server for .NET Administration UI or the seedeploy command-line utility.