Heaps, Clustered, and Non-Clustered Indexes

I started programming back in the year dot, at the grand old age of 10. My father acquired a Sinclair ZX80 for his engineering company and I was fascinated by it. I was soon trawling through the 110 page user guide and teaching myself the exotically named Beginner’s All-purpose Symbolic Instruction Code. Peek’ing and poke’ing and beep’ing and flash’ing, and generally amazing all comers with my sophisticated programming skills – 10 PRINT “HELLO WORLD” 20 GOTO 10.

A couple of years later I was treated to a Commodore 64. It was a joint birthday and Christmas present, and at just under £200 (equivalent to £800 today) I was a very lucky boy. This time the manual was a whopping 490 pages long, and I read it from cover to cover again and again.

I then upgraded to a Commodore 128. The user manual was a disappoiting 399 pages long. A step back from the Commodore 64. But what redeemed the situation was the 756 page “official” programmers reference guide, which I had to buy separately.

Computer magazines started to appear in the shops, but these focused on either basic programming tasks or games listings which you spent all day typing in and never ever worked. The local library had a few incomprehensible manuals, too technologically specific to be of relevance to anyone. This just about exhausted the information that was available, and so understandable each and every user manual and reference guide that I had was well loved, and well worn.

What I’m trying to say – in a very round about way – is that back then there wasn’t much information around. Learning and understanding was pretty much a matter of trial and error. Lot’s of perspiration and the occasional bit of inspiration. Today however there are a wealth of credible resources available. And YouTube has become one of the best of these. There are videos on most topic – some good and some bad. Occasionally I come across a gem. And I wanted to share one of those gems with you.

It’s by Voluntary DBA, and it describes the differences between heaps, clustered, and non-clustered indexes.  It’s an important topic, but one that typically is not described particularly well IMO. Voluntary DBA does as good a job and I’ve seen, and it’s well worth watching if you’re new to the topic, or need a refresher –

https://www.youtube.com/watch?v=ITcOiLSfVJQ

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