Ask HN: HNSearch.com hangs on upper bound

1)GOOD - works well as it reaches within the search result set limit http://www.hnsearch.com/search#request/all&q=Hackers&start=990&limit=10

2)BAD - hangs as limit goes beyond the max result set http://www.hnsearch.com/search#request/all&q=Hackers&start=990&limit=11

curious to know whether this is ThriftDB bug or HNSearch.com?