INF: Backing Up and Recovering Databases (62873)

SUMMARY

The following information describes some considerations for backing up or restoring databases:

1. When using log backups in combination with database backups, make sure you never truncate the log with either DUMP TRANSACTION WITH TRUNCATE_ONLY or TRUNCATE LOG ON CHECKPOINT. Any log backups following the truncation of the log are invalid and will generate an "out of sequence" error when restoring the transaction logs.
   
   DUMP TRANSACTION has its own form of syslogs truncation. Therefore, in version 4.2x, it is important that each transaction dump is dumped onto a separate device, and that all are stored and restored in the same order.
2. When only dumping databases, the transaction log must be truncated to keep it from becoming unnecessarily large because DUMP TRANSACTION does not truncate the log. In this instance, you should use TRUNCATE LOG ON CHECKPOINT.

Method 1 should be used for large databases so the whole database does not always need to be backed up. Method 2 is better suited for small databases.