Sybase World

Automatic Recovery Automatic recovery is a process the server’s executes during every startup to ensure that each database is restored to a consistent state. It happen every time the server is started Transaction A transaction is a logical unit of one or more Transact-SQL statements Consistent State All committed transactions are reflected on the database device Any transaction that was not committed is not reflected on the database device(s) Syslogs ( transaction log ) Typically the whole row is recorded in the transaction log. ‘selects’ are not recorded in the log b’ cos the don’t modify the database. Transaction log pages and their corresponding data pages are processed in the data cache Data cache Data cache is a portion of Adaptive Server memory where data, index and log pages currently in use by the server are held. When pages are not in use by the server, they are stored in the disk. When any modification is made the corresponding page (data, log or index ) is brought into the c...