To make it less ugly, and assuming you are using PostgreSQL you could make the code a little more appealing rewriting it like that. (If you are not using postgres WITH will probably not work but VALUES instead of UNION should still work). Please also notice that "binary" is quoted because it's a reserved postgresql word.

  WITH
  boxes(hostname, os, arch, ram) AS (VALUES
      ('box1', 'linux', 'x86-64', 8),
      ('box2', 'freebsd', 'arm', 16),
      ('box3', 'windows', 'x86-64', 4),
      ('box4', 'illumos', 'sparc', 4)
  ),
  compilers("binary",version,output_option) AS (VALUES
      ('gcc', '4.8.4', '-o'),
      ('clang', '3.4.1', '-o'),
      ('msvc', '15.00.30729.01', '/Fe')
  ),
  tests(name,sources) AS (VALUES
      ('frobnicate' , 'frbonicate.c' ),
      ('loadtest', 'loadtest.c helpers.c'),
      ('end2end', 'end2end.c helpers.c')
  )  
  
  SELECT *, compilers.binary || ' ' || tests.sources || ' ' ||
          compilers.output_option || ' ' || tests.name cmdline
  FROM boxes, compilers, tests
  WHERE NOT(tests.name = 'loadtest' AND boxes.ram < 8)

Here is a fiddle to play around... http://sqlfiddle.com/#!15/9eecb7db59d16c80417c72d1e1f4fbf1/1...

But this is a stand alone query, SQL really become useful IMHO if data is stored inside the DB or gathered automatically by the db. For the inheritance I'm really clueless, it depend on what you try to achieve and i'm just a DB guy.