Some observations on databases in general, implications when using COBOL, and a portal that provides data on SQL and Normalization

(c) Peter E. C. Dashwood - 2017

Here's the RDB Portal...

The following links are to information that we either produced or have found very useful when dealing with Databases.
LINK DESCRIPTION COMMENT

"The Path to Relational Database" is distributed with installs of the Migration Toolset. It describes (with examples) the things you need to watch out for when moving from ISAM to Relational database.

Although it describes use of the PRIMA tool, it also describes the common pitfalls and traps encountered during Migration. The same considerations are important even if you are building from scratch, if you intend to use COBOL with your database.

A document that describes NORMALIZATION in simple terms.

ALL PRIMA generated RDBs are Normalized to Third Normal Form (3NF), if that is possible. (It may depend on the key structures defined.) It is very rare for them NOT to be 3NF and they are always at least 2NF. Later versions of the Migration Toolset also include OPTIMIZATION which removes Group Fields and deals with REDEFINES. You CAN do it all yourself (everything you need to know is in the Pathway document) but it is MUCH easier to do it with a mouse click.

Learning the basics of SQL/DML...This is an excellent tutorial, and there is a quiz if you think you know SQL...

W3C Schools are one of the best free educational resources on the Internet. You can learn at your own pace and their teaching is simple and direct.

All about DDL...

In my opinion this site is the definitive one for matters SQL. There are many BAD tutorials scattered around the Internet. Poor English, non-Normalized examples, a lack of academic discipline and so on... This site is absolutely excellent; you can trust what he says.

ORIGINAL SQL page from the ORIGINAL COBOL21 site...

This is a highly compressed quick tour of SQL. It introduces a number of things but gives little or no detail on them. (It DOES give you a starting point of keywords to search further on.)

Use the back arrow or HOME link at the top of the page to continue navigation once you get to this page.

You may also want to Browser zoom on it (I find +130 pretty good) as the text is smaller...

Summarising...

Whether you are starting from scratch and designing and building your RDB, or you are trying to get an RDB that will accurately and efficiently reflect the data enclosed in your existing indexed files, there is a great deal to be considered and implemented. Do not underestimate the work involved and beware of people who say: "All ya gotta do...". Here are some RECOMMENDATIONS:

1. Use the PRIMA tools; they come with support from us... (Yes, I would say that... but you really should consider it. Contact us.)

2. If you are new to RDB technology, get someone who knows about it on site for a while to guide and advise. This is particularly important during the "design" phase of your RDB because a bad design, or something that perpetuates the inefficiencies in the existing system, will cost you more than having a consultant for a while.

3. If you are using COBOL and are more likely to be doing "record processing" than collecting ad hoc fields, definitely use the DAL approach. DAL is good no matter what language you use, but it is particularly good for use with COBOL.

(Use RIFFLE to continue navigating the site...)


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