# Retention Policies
Administrators can specify optional retention policies which use the ADO.NET Data Archiving and Shipping service in order to purge/obsolete data which is no longer clinically relevant.
When enabled, the retention policy feature will create a JOB on system startup which will ensure that data is retained according to the administrator configured policies.
| Option | Description | Example |
| ------------------ | ---------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------- |
| Policy Variables | Allows the specification of variables (like cutoff dates, environment variables, etc.) which can be used in the retention policy definitions. | Collection if .NET C# Expressions |
| Policy Definitions | The specification of one or more data retention policies which the policy retention service will apply. | See: [Retention Policy Definition](#undefined) |
| Job Status | When ENABLED the retention policy will be enabled on system startup. | ENABLED \| DISABLED |
| Repeat | The days of the week when the scheduled job of retention should be applied. | Day of Week |
| Start On | The date/time when the job should be started (time indicates the time the job will start) | DateTime |
| Stop On | The date/time when the job should no longer be triggered | DateTime |
| Stop This Event | When true, the Stop On property is enforced, when false the job will run on the schedule indefinitely. | Boolean |
| Interval | If you want to run the retention job on an interval rather than on a particular kickoff time each day of the week, use the interval here in seconds. | Number |
| Use Interval | When TRUE the interval value is used and the job is triggered on a regular timer. When FALSE the job is scheduled to execute on the Start On time. | Boolean |
## Retention Policy Definition
The retention service requires the definition of retention policies which need to be applied.
| Option | Description | Example |
| ---------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------- |
| Applies To | The resource type that the policy applies to.
Note: SanteDB Resources use inheritance so a binding to Person applies to Patient, Person, and Provider
| `Patient` |
| Exclude Filter | The HDSI query filters of objects which DO NOT APPLY to this retention policy. | See: [HDSI Query Syntax](https://help.santesuite.org/developers/service-apis/health-data-service-interface-hdsi/hdsi-query-syntax) |
| Include Filter | The HDSI query filters for objects which DO APPLY to this retention policy. | See: [HDSI Query Syntax](https://help.santesuite.org/developers/service-apis/health-data-service-interface-hdsi/hdsi-query-syntax) |
| Name | An informative name to show in logs and notifications. | `Males > 10 yo` |
| Retention Policy | The actual policy which should be applied to the retention of data. | See: [Retention Policies](#undefined) |
### Retention Policies
The retention policy on a policy definition indicates the action that the service should take on data which matches **Include Filter** but is not in **Exclude Filter**.
| Policy | Description | Example Action |
| -------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------ |
| Purge | Purges (permanently erases) data from the primary database. The data is no longer stored. For versioned resources, a resource pointer is maintained with a status key of PURGED. | Purge all Obsolete Patients |
| Obsolete | Obsoletes (logically erases) data from the primary database. The data continues to exist in the primary database however it does not appear in user interfaces. | Obsolete all Patients > 10 years old |
| Archive | Copies the data from the primary database (in the ADO.NET Data Persistence Service configuration) to the archive database (in the ADO.NET Archiving and Shipping configuration) | |