Sybase IQ uses the transaction log file during recovery from a system failure.
It does not use the transaction log to restore an IQ database, to recover committed IQ transactions, or to restore the catalog store for a Sybase IQ database. For a full restore, the transaction log must not exist. You must delete this file before starting a full restore.
SQL Anywhere databases use the transaction log and other logs differently. If you are recovering a SQL Anywhere database, you need its transaction log file, and BACKUP retains it for you. See SQL Anywhere Server – SQL Usage for details. Also, if you have data (other than the system tables) in your catalog store, transactions for that data can only be recovered if they were written to disk before a failure.