EXPLAIN EXTENDED

Back in the end of 90's I had been employed with a small startup which was founded to develop a restaurant management system.

The job listing they posted said PostgreSQL wanted (sic). And PostgreSQL for sure was something I knew about. You see, I already had experience with PostgreSQL by that time. I was able to install PostgreSQL, create a database, run a query against it and even create a trigger in C (I didn't yet know of pl/pgSQL).

So I applied for the job, got hired and started coding.

Coding what you may ask?

Well, I had no idea. And in fact, nobody did. There were only two requirements for the system.

First, it had to work somehow with a Casio Cassiopeia, which allowed a wireless network module to be installed and used. A waiter had to be able to take your order and it had to get to the kitchen instantly.

Second one was personal. The founders of the company (and me too) used to dine in a small cafe at the basement of the office building. They had a menu, but it didn't correlate with reality. You literally couldn't get anything that was in the menu. They were constantly out of meat, out of tomatoes, out of potatoes (potatoes!). Instead they put a small hand-written piece of paper into the menu which listed everything the had at the time (a soup and a something else), that's if they were in good mood. If they were not, you just placed an order, and a waiter came back in 10 minutes to tell you it was beyond their ability to get some tomatoes and cucumbers to chop you some salad, try ordering something else, thank you.

In our system, that was never ever going to happen. Never. If the kitchen was short of something they needed to cook you a dish you ordered, the system would warn the waiter instantly, and she would tell you to order something else right this minute, that's instead of going to the kitchen and back.

It had to be a killer feature.
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