INF: Backing Up and Recovering Databases

ID Number: Q62873

1.10 1.11 4.20

OS/2

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,

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.

Additional reference words: Dumping and loading