When you do not have enough server threads to initiate the query you have issued, you get the error:
Not enough server threads available for this query
This condition may well be temporary. When some other query finishes, threads are made available and the query may succeed the next time you issue it. If the condition persists, you may need to restart the server and specify more Sybase IQ threads, as described in the next section. It is also possible that -iqmt is set too low for the number of connections.