> For the complete documentation index, see [llms.txt](https://docs.videc.de/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.videc.de/acron-9.3/en/ac_admin/acron_datenbank-engine.md).

# ACRON Database Engine

The ACRON Database Engine manages your plant data. It must run once for each plant on the ACRON Database Server and is responsible for the administration and organization of the ACRON database.

The ACRON Database Engine performs the following tasks:

* Continuous re-compression for fixed time range data
* Compression of variable time frames on request
* Reorganization and optimization of the database in terms of size and access speed
* Checking of hard disk space
* Deletion of temporary files and plant data beyond the archiving time limit.

#### Install the service from the command line:

`DBEngineService` \<Plant identification> `/I`

#### Remove the service from the command line:

`DBEngineService` \<Plant identification> `/U`

Note

The Database Engine can be caused to recalculate older data by changes in the following areas:

1. Provider History data
2. Provider Data transfer after network failure
3. ACRON Mirror / Data synchronization
4. Reporter Manual entries
5. Reporter Overwritten values
6. Designer Configuration / Events
7. Designer Configuration / Process variables
8. Designer Configuration Process connection / Modify external variables
9. Designer Plants / Options
10. Designer Plants / Database
11. Admin / Plant / Restore plant
12. Designer Plant / Configuration check
13. Designer Plant / Database / Check
14. Designer Plant / Recalculation / All compression data
15. Designer Plant / Recalculation / Selected compression data...
16. Designer Plant / Recalculation / All events
17. Designer Plant / Recalculation / Selected events...


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