You might think that SQL Anywhere would run faster without a transaction log because it would have to maintain less information on disk. Yet, the opposite is actually true. Not only does a transaction log provide a large amount of protection, it can dramatically improve performance.
When operating without a transaction log, SQL Anywhere must perform a checkpoint at the end of every transaction. Writing these changes consumes considerable resources.
With a transaction log, however, SQL Anywhere need only write notes detailing the changes as they occur. It can choose to write the new database pages all at once, at the most efficient time. Checkpoints make sure information enters the database file, and that it is consistent and up to date.
Always use a transaction log. It helps protect your data and it greatly improves performance.
If you can store the transaction log on a different physical device than the one containing the main database file, you can further improve performance. The extra drive head does not generally have to seek to get to the end of the transaction log.