Microsoft Corp has turned to Hewlett-Packard Co and Adaptec Inc for proof of concept that its forthcoming SQL 7.0 database can handle something it is calling active backup – technology that enables a database to continue processing transactions during backup, with minimal impact on transaction throughput. Working with Microsoft and Adaptec, HP said it has measured database backup performance of over 100Gb per hour while 250 simulated users continued processing online transactions. Running a medium transaction processing workload on an HP NetServer system, SQL Server 7.0’s concurrent backup facility maintained online transaction throughput at a rate of 88% during the backup. But the speed of the backup itself is reduced almost by half, however: an idle database running on the same system achieved backup rates of 195GB an hour. HP used a NetServer LX Pro system for the tests, with four 200MHz Pentium Pros, NT server 4.0, 12 HP SureStore DLT 70 tape drives and Adaptec’s 3940A-UW dual port UltraSCSI interface cards. The database size was 144Gb residing on 44 disk drives. Oracle Corp, however, was less than impressed. Welcome to the 1980s said a spokesperson, we’ve been doing this since 1988. Oracle said online backup was regarded as normal operational procedure and that its own throughput rates would not dip lower than 95% during backups. It also pointed out that database consistency checking can’t yet be done on line with SQL Server, and would entail extensive offline processing for large databases.
