Reorg rebuild Tablename Indexname allows the table to still be used while the reorg is running.
Reorg rebuild tablename (without the index) causes the table to be blocked.
Reorg Compact is a good way of dealing with forwarded rows while the table is still actively being used.
Reorg Index maintenance and Reorg Compact maintenance are great ways of dealing with huge tables that cannot afford downtime.
I have not used the time options for the reorg command.
I believe it is better to use the "Reorg Compact" followed by "Reorg Rebuild Tablename Indexname"...
because the reverse would disturb cleanly built indexes.
Keep reading this blog as time goes by to see how I improve my table performance.