During recovery, Adaptive Server reads each log page that includes records for a transaction and then reads all the data and index pages referenced by that transaction, to verify timestamps and to roll transactions back or forward. Then, it performs the same work for the next completed transaction, until all transactions for a database have been processed. Two separate asynchronous prefetch activities speed recovery: asynchronous prefetch on the log pages themselves and asynchronous prefetch on the referenced data and index pages.
