Procedure documentationMaking Snapshots of the Data Area Locate this document in the navigation structure

 

A snapshot is used to save the current state of the data area.

Caution Caution

A snapshot is not a data backup. To be able to restore your data after damages to the data area, regularly backup your database.

Also note that snapshots are not part of data backups. If you have to recover your database using data backups, you lose all snapshots in the process.

More information: Backing Up Databases

End of the caution.

To create and manage snapshots, the database system uses a shadow memory concept: a snapshot saves the current converter. Data changes that you make after the snapshot are written by the database system to other physical pages in the data area. For example, if you delete a table, the database system does not physically delete this table, but only flags it as deleted (and you can no longer access this table with SQL statements).

Procedure

  1. Create the snapshot.

    More information: Database Studio, Making Snapshots of the Data Area

  2. After you have created the snapshot, you can continue to work normally and change data in the database without influencing the snapshot.

  3. At a later time, you can do the following:

    • You return to the state of the data area at the time of the snapshot, thereby rejecting all changes made since the snapshot. The snapshot contains all necessary information; you do not need a data backup for this.

      More information: Database Studio, Undoing Changes Since a Snapshot

    • You delete the snapshot, thereby permanently transferring all changes that were made after the snapshot to the data area.

      More information: Database Studio, Deleting Snapshots

Example

You set up a computer for training purposes.

  1. Import a complete data backup from the original database onto the training computer.

  2. Create a snapshot.

  3. The database is now available for training purposes. The participants in the training course can now change data and start and stop the database.

  4. After the end of the training course and before the start of the next training course, discard all changes since the snapshot.

More Information

Concepts of the Database System, Converter