*** pgsql.old/doc/src/sgml/func.sgml 2005-05-23 03:50:01.000000000 +0200
--- pgsql.new/doc/src/sgml/func.sgml 2005-06-01 19:17:08.000000000 +0200
***************
*** 279,284 ****
--- 279,300 ----
a < x OR a > y
+ There is special variant of this operator BETWEEN SYMMETRIC.
+ In this case isn't important x <= y and
+ a BETWEEN SYMMETRIC x AND y
+ is equivalent to
+
+ (a >= x AND a <= y) OR (a >= y AND a <= x)
+
+ Similarly,
+
+ a NOT BETWEEN SYMMETRIC x AND y
+
+ is equivalent to
+
+ (a < x OR a > y) OR (a < y OR a > x)
+
+
There is no difference between the two respective forms apart from
the CPU cycles required to rewrite the first one
into the second one internally.