SAP IQ : Empty select query without warning or error message

Hello,

We face a strange issue with our IQ DB.

Sometimes, a "simple" SELECT query returns no records (but there are matching records in the DB) and the DB does not throw any error message nor any warning message.

Re-executing the same query a few time (sometimes just a couple of minutes later) and the DB sends the correct records.

Here is an example of the query.

select DISTINCT a.c1, a.c2, a.c3, FIRST_VALUE( b.c1 IGNORE NULLS ) OVER ( PARTITION BY b.c2,b.c3 ORDER BY convert(numeric,b.c4) ASC RANGE BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING), from schema1.table1 a, schema2.table2 b where(1=1) And (a.c1=b.c2 AND a.c2=b.c5)

Thanks by advance.

Regards,

Alex.

DB Informations

Sybase IQ (TM)Copyright (c) 1992-2010 by Sybase, Inc. All rights reserved.

Version:15.1.0.5043/100427/P/ESD 3/Enterprise Linux64 - x86_64 - 2.6.9-67.0.4.ELsmp/64bit/2010-04-27 11:00:14

File Format: 23 on 03/18/1999

Server mode: IQ Server

Catalog Format: 2