Synchronization can be time-consuming. To improve performance, try these suggestions:
Schedule synchronization during off-peak hours.
Synchronize join indexes individually rather than all at once.
Synchronize after executing an entire set of insertions and deletions. It is not a good idea to synchronize after every insertion or deletion, as the time it takes to update a join index depends significantly on the order of the updates to the tables. Synchronizing sets of updates allows Sybase IQ to pick the optimal order for applying the table changes to the join index.