Unconstrained deletion of objects of studies from storage system triggered by deletion threshold

[gunterze]

Unconstrained deletion of objects of studies from storage system triggered by deletion threshold.

Supported by configuring Storage attributes:

Name	Value	Description (LDAP Attribute)
Storage Duration	CACHE	Indicates if the Storage is used as permanent (=PERMANENT), cache (=CACHE) or temporary (=TEMPORARY) storage. Objects get purged from cache and temporary storage according configured deleter thresholds or - if no deleter threshold is specified - all objects on the Storage will get purged. In the case of temporary storage, the studies which objects were purged are also deleted from the database. Enumerated values: PERMANENT, CACHE or TEMPORARY. (dcmStorageDuration)
Read Only	false	Indicates if a Storage System is read only. (dcmReadOnly)
Deleter Threshold(s)	<Threshold>	Minimal Usable Space on Storage System to trigger deletion. If present, studies are deleted from the Storage System, if the usable space fall below that value. Format [nn’[‘’]’]nnn(MB|GB|MiB|GiB) (dcmDeleterThreshold)
External Retrieve AET	<none>	Constrains deletion of Studies from the Storage System to Studies which objects are retrievable using this AE from an external C-MOVE SCP. (dcmExternalRetrieveAET)
Export Storage ID	<none>	Constrain deletion of Studies, if usable space falls below the configured threshold, to Studies which objects are also accessible from the specified other storage. (dcmExportStorageID)