Considerations for trimming archived data from ION_Data
When archiving and then trimming data from the ION_Data database, you are moving this data from the operational database into an archive store for long-term retention. This data is then no longer available in the ION_Data database for analysis in PME. PME has very limited access to archived data.
We recommend that you only trim archived data from the ION_Data operational database, when:
- It approaches its size limit, for example 10 GB for a SQL Server Express database.
- It reaches a size that impacts query performance.
- The database drive is low on available free space and you cannot switch to a larger drive.
When you trim data from an SQL database, the database file size remains unchanged. After the trim, the database will first fill the new free space before growing the database file size again. To reduce the database file size after trimming, Shrink the database, using standard SQL Server tools.
NOTE: The PME archive task does not trim the database; it only copies data to the archive.
Archive data access in PME:
| Application | Archive Data Access |
|---|---|
| Vista | Yes |
| Reports | Can access either data from the operational database or from an archive database but not both at the same time. |
| Dashboards | No |
| Diagrams | Yes |
| Trends | No |
| Alarms | No |