Commented by: @dyemanov

Am I right that you complain just about the limit being actually 1499 instead of 1500?

Commented by: Andreas Steibl (snoopy_spy)

yes, the old version (about 1.5) can use exactly 1500 items, but the newer one has this bug - is this a allready known bug? (i didn't found anything about it)

Commented by: @dyemanov

This is a known issue, although I'm pretty sure that all previous FB versions have the same limit of 1499 items.

Commented by: Kjell Rilbe (kjellrilbe)

Since the actual limit per se can't really be very important to anyone (right?), I'd suggest simply to make the current limit official by changing the docs.

Commented by: Kjell Rilbe (kjellrilbe)

Also, I'm a bit curios, why is there actually a limit to this? Couldn't FB simply allow as many items as fits in the 64 kbyte query buffer?

Commented by: @dyemanov

The IN predicate is just a syntax sugar, from the implementation POV it's a shortcut for a set of ORs. And any ORed or ANDed predicates are processed recursively, thus causing stack overflows for a big number of elements. Perhaps the original assumption was that nobody sane would be typing so many ORs/ANDs but it may be much easier with IN (list), hence the recursion limit.