LinkLog: Programmer Competency Matrix

On a winter day in Boston, I sat through a two hour lecture on B-Trees. There was snow outside and we all sat spell bound as Greg Basset, our instructor taught us how Digital’s RMS-11K (the record management system) worked. The concept of incremental loading, fill factors, splitting data and index buckets and compression of duplicate keys, is still fresh in my memory. I gave that talk several times later in my life when I was teaching the subject. In each repetition, I learned a little bit more, answering questions. A few years later, I had the chance to use many of the ideas when we built C-Trieve and Objectrieve, two record management systems on top of which we built an SQL relational database. That was more than a couple of decades ago.

Looking at the Programmers Competency Matrix brought back lots of those memories. I think I am going to make a custom version of this matrix, make a poster and put it up on the wall of my class. A lot of these topics are not needed for the application programming today. But for a few of those intensely curious students, this is a kind of road map.


Reddit is a great source of interesting posts, especially for programmers. I should thank the kind soul who posted this link.

6 thoughts on “LinkLog: Programmer Competency Matrix

  1. Hi Dorai,

    I check out your Blog once in a while and ALWAYS find something that is immediately USEFUL to me – such as this Programmer Competancy Matrix. So thanks, and keep it coming.


  2. Shantha,
    Thanks. is probably one of the best resources for articles related to software. It is one of my favorite. Many of my blog posts are inspired by an article posted there.

    Good to see you here.


  3. Hi Dorai,

    This is RP. I was searching for the C-SQL Engine design document by someone at Xenix (we had a copy) and I came across this tidbit of Cosoft history by you.

    My interest in that document is because it is one of the most lucid document on such a complex thing as a DB Kernel. It helped me “fix” a bug which allowed a sub-queries in BETWEEN (BETWEEN SQ1 AND SQ2) which wasn’t allowed by SQL Std at the time.

    The person’s first name was Steve. Could you try to recollect it, and possibly locate it? It belongs in the same class as K&R, The Design of UNIX Operating Systems and The Design and Implementation of 4.3 BSD UNIX.

    1. RP,
      The only person who did any documentation for Integra SQL was Bob Stayton from SCO who did Xenix. The other person who did any work was Louis Bozeck. Don’t recall working with any one called Steve.

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