Author: Paweł Zabrowski

Chief Systems Architect at e-point

Pitfall in Oracle Database: An Empty Text Stored as Null

I like Oracle database. It is efficient, easy to use for beginners and professionals – its tools for query analysis and optimization are masterpieces. But it has a very annoying “feature” – empty text (containing 0 characters) is stored in the database as null.Where did such a feature come from?Probably from the ancient ages, just after the dawn of time, i.e., the late 70’s [1] . In that age, memory (RAM and disks) was very limited and system designers did their best to use as little memory as possible. In old versions of Oracle DB,

Give the toys back to your children!

You may not believe it but the items in this picture are not just kids’ toys; they areimportant partsof the software development process! We call them “database tokens.”When there are multiple developers on the project and you are not creating a few java classes for yourself, you need a versioning system which stores files with the source code. We use GIT, which allows developers towork simultaneouslyon the same module or even on the same Java file.

When Normal Forms are Not Enough

A real-life example:Let’s assume that we have a system which stores data fordistributorswho sell products manufactured by some company. Each distributor receives points for selling products and may redeem a specified number of points to obtain a discount or extra bonus. Points are calculated byan external systemand updatedvery frequently– after processing of each order placed by the distributor himself, a member of the distributor group, or a customer assigned to the distributor. The distributor is identified using a distributor number. We are using a DB2 database.