Large table extents

Can anyone answer the following questions? 1. When rows are deleted from a table, are the remaining rows left scattered over the table extent? 2. When these remaining rows are queried, given that 1. is true, does Informix sequentially scan through the whole table extent including empty pages? I ask this because that is what seems to be happening and if it is, then we need a way to defragment the table extent. I would think that this means unloading and re-loading the table. Is there anything else that can be done to stop this kind of fragmentation? Thanks for your time. Stanton Attree.