Just how popular is PL/SQL?
And how many PL/SQL developers are there "out there"?
These are surprisingly hard questions to answer. Officially and even unofficially, Oracle Corporation's point people on PL/SQL do not have any idea (or refuse to say) how many PL/SQL developers there are.
I take the approach of doing some rough extrapolations from numbers of books I and other PL/SQL developers have sold, and I conclude that there are perhaps a couple million PL/SQL developers, all told.
That is, however, very unscientific.
There are some websites, however, that offer an analysis of relative popularity of languages, usually based on data they have retrieved from various search sites.
TIOBE
Here is the list as of January 2008:
Ok, fine, so PL/SQL is not the most popular language. We all know that. What I was very pleased to see is that PL/SQL had increased in popularity over the last year. Based on my experience in India, I can see why; most of the increase probably came from there alone!
Here is some information from the TIOBE website about how they calculate their ratings:
- The ratings are calculated by counting hits of the most popular search engines. The search query that is used is: +" programming"
- The search query is executed for the regular Google, Google Blogs, MSN, Yahoo!, and YouTube web search for the last 12 months. The web site Alexa.com has been used to determine the most popular search engines.
- The number of hits determine the ratings of a language. The counted hits are normalized for each search engine for the first 50 languages. In other words, the first 50 languages together have a score of 100%.
Let's define "hits50(SE)" as the sum of the number of hits for the first 50 languages for search engine SE and "hits(PL,SE)" as the number of hits for programming language PL for search engine SE, then the formal definition of the ratings becomes
((hits(PL,SE1)/hits50(SE1) + ... + hits(PL,SEn)/hits50(SEn))/n
where n is the number of search engines used.
LangPop
The nice thing about the TIOBE site is that they rank PL/SQL explicitly. All the other language popularity pages I could find simply list "SQL," which I took to mean "SQL and all procedural language extensions to SQL."
O'Reilly Media Popularity by Book Sales
O'Reilly Media, publisher of all my books on PL/SQL, has a research arm ("O'Reilly Radar") that projects programming language trends based on book sales. Again, there is just a single entry for SQL: