Backing Up and Recovering Databases

This chapter describes the following backup and recovery features of Ingres:

• Checkpointing and journaling to back up a database or selected tables
• Unloading a database
• Copying a database to back up particular tables or all objects you own in a database
• Using operating system backups to replace current or destroyed tables in a database
• Roll forward of a database to recover a database or selected tables from checkpoints and journals

You should back up your database regularly so that you can recover your data if necessary. Databases or tables can be damaged accidentally by hardware failure or human error. A disk crash, power failure or surge, operating system bugs, or system crashes, for example, can destroy or damage your database or tables in it.

Full or Partial Recovery

Ingres allows you to perform full recovery, which involves recovering an entire database, or partial recovery, which recovers selected tables in a database.

Partial recovery entails recovering data from a backup copy at a level of granularity finer than the entire database. In the event of failure, Ingres can, if possible, mark less than the whole database physically inconsistent. The advantage of partial recovery is that it reduces recovery times by requiring only recovery of logically or physically invalid data.