Certain meta characters dont parse well while adjecent to each other.

e.g.
VALUES('y' SIMILAR TO 'x*+y'); -- returns true
VALUES('y' SIMILAR TO 'x+*y');
Error: java.util.regex.PatternSyntaxException: Dangling meta character '*' near index 2
x?*y
  ^ (state=,code=0)

Interestingly, VALUES('y' SIMILAR TO '(x+)*y') returns true.

This may very well be expected behavior. However, I verified on postgreSQL install, both patterns return illegal regex error. If farrago behavior is indeed SQL:2008 compliant, then we need to make sure there is elaborate section on regular expressions explaining these cases in farrago documents.