对数函数

-- With Settings.transformPatternsLogarithmicFunctions active, this:
SELECT
  LN(value) / LN(base),
  EXP(1),
  LOG(e, x),
  LOG(10, x),
  POWER(e, x)
FROM tab;

-- ... is transformed into the equivalent expression:
SELECT
  LOG(base, value), -- LN(value) / LN(base)
  e,                -- EXP(1)
  LN(x),            -- LOG(e, x)
  LOG10(x),         -- LOG(10, x)
  EXP(x)            -- POWER(e, x)
FROM tab;