previous : next

Available in versions: Dev (3.20) | Latest (3.19) | 3.18 | 3.17

This is experimental functionality, and as such subject to change. Use at your own risk!

Repeated bitwise negation

Applies to ✅ Open Source Edition ✅ Express Edition ✅ Professional Edition ✅ Enterprise Edition

The bitwise negation unary operator reverses itself, when called repeatedly, meaning that redundant BIT_NOT() operators can be removed.

Using Settings.transformPatternsBitNotBitNot, the following transformations can be achieved:

-- With Settings.transformPatternsNegNeg active, this:
SELECT
  ~(~(x)),
  ~(~(~(x)))
FROM tab;

-- ... is transformed into the equivalent expression:
SELECT
  x,  -- ~(~(x))
  ~x, -- ~(~(~(x)))
FROM tab;

previous : next

References to this page

Experimental features

Feedback

Do you have any feedback about this page? We'd love to hear it!