$ whois q

Q

first released in 2003 · by Arthur Whitney

$ guessprog --inspect q

year: 2003
paradigm: array oriented
family: apl
memory: automatic gc
binding: dynamic
safety: strong

Q(7)

AUTHORS: Arthur Whitney
HISTORY: Arthur Whitney created q at Kx Systems in 2003, as the language of the new kdb+ database. It is a thin, more readable layer over his terse array language K: many one-character K primitives get English names such as til, sum and where. It also adds qSQL, a query syntax that looks like SQL but works directly on in-memory, column-oriented tables. Like K, q evaluates expressions from right to left.
USAGE: A niche, proprietary language that is well known in finance, where kdb+ and q are used by banks and trading firms to store and analyse huge volumes of market tick data.
SEE ALSO: Q on Wikipedia ↗

$ cat trades.q

/ a table of trades, built from column lists
trade:([] sym:`AAPL`MSFT`AAPL`GOOG`MSFT;
  price:189.5 410.2 190.1 141.3 409.8;
  size:100 200 150 300 50)

/ qSQL: volume-weighted average price by symbol
select vwap:size wavg price, total:sum size by sym from trade

/ functions use implicit arguments x, y and z
f:{x*x}
f til 5          / 0 1 4 9 16