One of the most difficult thing in using IMS is accessing data. Unlike DB2 and other relational databases, IMS does not have an English-like query method. To access a database, you either need to code a program or use utilities like FileAid for IMS.
Likewise, if you want a graphical representation of IMS, you need to understand the DBD definitions and learn how to interpret them.
That is true until now. IBM released IMS Explorer which allows you to view your databases graphically and also access your IMS data graphically. It is free for download.
Installation
Installing the IMS Explorer is relatively easy. You will need to register at the IBM website. You will have to download the IBM Installer and the IMS Explorer files.
Install the IBM Installer first. Once done, you can install IMS Explorer.
Setting Up
You need to set up IMS Explorer to be able to use it. You can either download all your DBD sources and your PSB sources. You can then import them to IMS Explorer.
Another way to import these to IMS Explorer is to have it connect to the mainframe and use these source directly from the mainframe. I have not used this feature since I would not want to accidentally mess up the source code on the mainframe.
DBD
In any case, once you have imported these codes, you can view your databases graphically. If you have logical children connected to your database, you can also opt to show them. Once displayed, you may actually change your DBD definitions.
PSB
IMS Explorer also allows you to display your PSBs. It will show you the different PCBs in your PSBs. You can also change the attributes of these PCBs.
Accessing IMS Databases
One of the neat things you can do with the IMS Explorer is to access your IMS databases on your PC. You don't have to learn DL/1. You can actually access them using SQL! You will need at least IMS 11 to be able to use this function.
IMS Explorer basically treats your Database as a schema. Segments are treated as Tables. Fields are treated as columns. IMS Explorer generates metadata to manage this.
You can join various segments within your database - like joining tables within the same schema. You cannot, however join segments outside of your database. Once you have access the data, you can view, update, insert and delete your data.
In the past few years, IBM has been trying to make the mainframe more easy to use. This tool is a step in the right direction.
Philip Yuson - I have more than 20 years of experience in IT in three countries. I have been doing consulting for more than 10 years specializing in IT ...
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