k/q/kdb+ are often touted as having C speed, and the architecture of the interpreter is always cited. In my experience raw performance can be compared to python (or R) for iterative work and numpy for vectorised workloads.
It is an array language and focused on storage and numerical processing of large vector oriented datasets. Its speed as a general programming language is overrated and we often offloaded things to C.
I personally love APL derived languages, but its mystique has fostered a lot of hype.
A simple example, write a for loop with dependent data flow. There is not much optimization.
Is it possible that mandating vectorised solutions and avoiding I/O were in fact design goals of the author?
Not disputing the comment. Looking for more details.