By default Sybase IQ cursors are scrollable, meaning that Sybase IQ keeps all the query results in a buffer so that you can scroll backwards. If the query returns very large numbers (millions) of rows of output, you can improve performance by issuing the following command before running the query:
SET TEMPORARY OPTION Force_No_Scroll_Cursors = 'ON'
Some front-end applications make use of scrolling cursor operations, however, and require this option to be set “OFF”.
If scrolling cursors are never used in your application, you should make this a permanent public option. It will use less memory and make a modest improvement in query performance.
