Some Entity Relationship Diagrams (ERDs) are simple, while others are really complex. This article describes a few tools that can help you tackle both types of ERDs, as well as everything in between.
The first tool you’ll need sits right between your ears: your brain. There’s a lot to learn, and you’ll have to put your grey matter to use in this chapter. It’s also a good idea to review the Data Definition Language (DDL) part of SQL, because we’re going to revisit tables, views, indexes, constraints, and other DDL concepts. At some point, my SQL 101 TechTip series will touch on that, but for the time being, I’ll assume you’ve done your homework and are up to speed on these concepts.
First, a personal disclaimer: I’m not associated with, sponsored by, or engaged with the companies and/or products mentioned in this article. These are the tools that I believe provide the best solution at the lowest cost in a database modernization initiative. (Note that I’m not talking only about the monetary cost, but also about time.) There are many tools in the IBM i modernization market. While I suggest you should at least have a look at those listed here, seek the advice of your modernization consultant because your particular scenario might require a different set of tools.
Having said that, let’s start with a couple of IBM products. IBM Data Studio and IBM InfoSphere Data Architect are two data manipulation and modeling products that can help automate some of the tasks I’ll talk about later in this chapter. I won’t go into depth about these products, but I’ll give you a quick overview of each.
IBM Data Studio
Data Studio provides database administration and database development capabilities for DB2. It is the primary tool for production database administration for DB2 for Linux, UNIX, and Windows environments, but it also supports object management and routine development for DB2 for z/OS and DB2 for i.
For data and database object management, Data Studio provides a large array of features. In this particular context, here are some of the most relevant:
- Connect to DB2 data sources; filter, sort, and browse data objects and their properties.
- Import and export database connections.
- Use data diagrams to visualize and print the relationships among data objects.
- Use editors and wizards to create, alter, or drop data objects.
- Modify privileges for data objects and authorization IDs.
- Analyze the impact of your changes.
- Copy tables.
- View and edit table data.
- Reverse-engineer databases into physical models.
- Compare and synchronize changes between models, databases, and the DDL used to define objects in the database.
- Create, validate, schedule, and run command scripts.
Data Studio is a free tool that you can download from IBM’s web site. It might be a good idea to also download the free e-book Getting Started in IBM Data Studio from the IBM Data Studio product page.
IBM InfoSphere Data Architect
IBM InfoSphere Data Architect is an enterprise-level data modeling tool. It is a comprehensive development environment that you can use to model diverse and distributed data assets, as well as to find and establish relationships between those assets. Just like Data Studio, this product has a large array of features. In a database modernization context, the most important are the following:
- Discovering the structure of heterogeneous data sources by examining and analyzing the underlying metadata
- Allowing you to browse through the hierarchy of data elements (physical and logical files, tables, and so on), while displaying detailed properties for every element, through its accessible user interface
- The ability to create logical, physical, and domain models for DB2, Informix, Oracle, Sybase, Microsoft SQL Server, MySQL, and Teradata
Elements from logical and physical data models can be visually represented in diagrams using Information Engineering (IE) notation. Alternatively, physical data model diagrams can use the Unified Modeling Language (UML) notation. InfoSphere Data Architect enables data professionals to create physical data models from scratch, from logical models using transformation or from the database using reverse-engineering.
Unlike IBM Data Studio, InfoSphere Data Architect is not free, but the 30-day trial version is fully functional. There’s also a free e-book, called Getting Started With InfoSphere Data Architect, which will be of great use in learning how the tool works.
These tools can be very useful to understand and represent the existing and future database. However, they won’t solve the conversion or data migration issues you’ll be faced with. That’s where the next tool comes into play.
Adsero Optima Foundation
Adsero Optima Foundation is a complete package designed to ease one of the most important parts of the database modernization process: the DDS-to-DDL migration. This is a totally native solution that supports the automatic, gradual, and non-disruptive migration of legacy database objects (DDS-defined physical and logical files, for instance) to the native DB2 SQL (SQE) engine. As you’ll see later, the ability to automate the conversion of DDS to DDL data objects is crucial to a smooth database modernization, because it frees you up for the next and more-complex steps of the modernization process. This tool’s provided functionality goes beyond the first step of the process, however; it can help with the whole process of modernizing the database, going as far as automating some steps.
But that’s something I’ll discuss on the next article, which will be about database modernization methodology. In the meantime, I’d like to hear from you! Let me know what you think about this subseries and how I can improve it.