"Ian Bell" <ib@xxxxxxxxxxxxxxxxxxx> writes: > I just tried your suggestion and it generates the same error. For > verification, here is the function run in the debugger. I just realized that "syntax error at position N" is *not* the exact spelling you would get from a syntax error in PG's main parser, which I think is what we were all assuming this'd trace down to somehow. What it is is the (very poorly chosen) message you get if either ltree_in() or lquery_in() doesn't like what it's been handed. So basically, the problem here is that TestLtree() is being called with a string that isn't a valid ltree representation. You haven't shown us what you are doing on that end, but for example I can duplicate the error message with # select text2ltree(' '); ERROR: syntax error at position 0 regards, tom lane