The data in join index tables must be synchronized before you can use a join index. Synchronization ensures that the data is loaded in the correct order for the joins.
Synchronization occurs automatically when you create the join index. Synchronizing before completing the transaction that loads or inserts data also makes tables available immediately for all readers. Once data is loaded, however, you must synchronize the join index explicitly, with one exception: the join index is synchronized automatically when changes are made to the top table of the join hierarchy.
SYNCHRONIZE JOIN INDEX [join-index-name [, join-index-name]
If you omit the index names, Sybase IQ synchronizes all
join indexes.