A metadata file that describes the IMS™ database view is required for IBM® Mashup Center to access IMS data through SQL queries.
Development phase of an IMS database feed
For IBM Mashup Center to access an IMS database through standard SQL queries, it needs information about the database. Because IMS databases are hierarchical, you must use the IMS Enterprise Suite DLIModel utility plug-in to translate IMS source files into metadata files. The metadata files describe the relational database view that IBM Mashup Center can use to generate SQL queries. The IMS Enterprise Suite DLIModel utility plug-in is a separate tool that you can download from the IMS SOA Integration Suite Web page at www.ibm.com/software/data/ims/toolkit/.
A feed service application developer first generates the metadata file from the IMS program specification block (PSB) and database description (DBD) source files. The generated metadata file (a .class
file) needs to be compiled and copied into specific locations in IBM Mashup Center.
The developer then creates an IMS database feed in IBM Mashup Center by selecting Enterprise Database (JDBC)
, and providing connection information. The feed is registered in the catalog.
The following diagram describes the development phase of an IMS database feed.
Figure 1. Development phase of an IMS database feed in IBM Mashup Center
Runtime phase of an IMS database feed
When the IBM Mashup Center receives an HTTP request for an IMS database feed from a Web client, it passes the request to the enterprise database feed generator. The enterprise database feed generator constructs the SQL query and sends it to the IMS Universal DB resource adapter that is deployed in WebSphere® Application Server. The IMS Universal DB resource adapter communicates with IMS Connect, which handles the communication with the IMS database.
Figure 2. Runtime phase of an IMS database feed for IBM Mashup Center