Dumping and loading relaxed-durability databases is identical to dumping and loading full-durability databases. During a dump of a relaxed-durability database, Backup Server reads directly from the disk-based database devices, During a load, Backup Server writes directly to these devices by copying over pages from the dump archive. You can improve dumping and loading performance by using striped devices for relaxed-durability databases.
Because in-memory databases do not use disk devices, Backup Server reads pages directly from Adaptive Server shared memory during a dump, and writes it to the archive medium. During a load, Backup Server reads pages from the archive medium (for example, tape) and writes the load directly to the pages of the in-memory storage cache. Because in-memory databases do not use disk I/O to read or write pages on the server, the dump and load performance for in-memory databases is generally superior to that of disk-based databases of the same specifications.
During the dump and load commands, Backup Server opens one CT-library connection per stripe to Adaptive Server, and creates a communication channel to read database pages directly from Adaptive Server shared memory.
Backup Server synchronizes directly with concurrent tasks active in Adaptive Server while reading pages directly from its shared memory. To support load database recovery, Adaptive Server disables the strategies described in “Performance optimization for low-durability databases” for the duration of the dump operation. This may reduce the performance of transactional activity during the dump database command.
