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limiting how long deleted data is kept RSS feed
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Mike M

Joined: Aug 12, 2016
Messages: 47
Is there a way to purge old deleted data, either manually or automatically? I have a folder on my computer X. If I lose data in X, I'd like to have the following capabilities:

(1) restore any data that was currently present at the time of the loss of X

(2) restore data that was accidentally deleted from X by retaining deleted data for a few months

#1 is a basic backup/restore function, as you would expect. #2 means I want to keep deleted data, as QRecall normally does, but I don't want to keep it more than, say, three months.

James Bucanek

Joined: Feb 14, 2007
Messages: 1568

There are two reasons an item will exist in an archive: it was captured in a layer or it has been preserved as a deleted item.

tl;dr: captured items in older layers are preserved until they are merged with more recent layers. The "Keep deleted items..." option will ensure that deleted items are kept in the archive for a minimum period of time.

Here's the long-winded explanation...

Items in layers

The first should be obvious. Each capture creates a "layer" in the archive that represent a snapshot of all of the items at that moment in time. Let's take this example:

  • Create a document on Monday. Preform a capture

  • Delete the document on Tuesday. Perform a capture.

  • Your archive now has two layers. The first layer contains the document, the second layer does not. As long as both layers exist, you can always rewind the archive back to the first layer (using the layer shade) and recall the document as it was captured on Monday.

    The document in the first layer will exist in the archive until that layer is merged with a subsequent layer. Merging the two layers combines them and keeps only the most recent state. Since the document didn't exist in the second layer, the document will not exist in the merged layer.

    To answer your first question, merging layers is the natural way in which old documents, or old versions of documents, get deleted from the archive. As layers are merged, older items are discarded, and their space in the archive reclaimed. You can automate this using a merge action. How often you merge layers, and the granularity of those merged layers, determined how long captured items will remain in the archive.

    Keep Deleted Items

    Merging layers can sometimes discard items in a seemingly haphazard fashion, particularly for short-lived items. For example, let's say that you capture every day, periodically merge all of the layers captured during the week into a single layer (using a rolling merge action), and you keep the past 52 such layers in your archive.

    A document that was created on Friday and deleted the following Monday will persist in the archive for at least a year. (The document existed at the end of the week, so it will exist in the merged layers for that week, and you keep 52 such layers, so the document will be kept for at least 52 week.) On the other hand, a document created on Monday and deleted on Friday won't exist in the archive for more than a couple of weeks. (When the layers for that week get merged, the document is purged because it didn't exist at the end of the week.)

    To combat this capricious behavior, the archive has a "Keep deleted items for at least:" setting (see Archive > Settings....). If you set this period then a merge action will preserve the last version of a deleted item that would normally be discarded, if that item existed within the period you set.

    Going back to the Monday-Friday example, if your "Keep" setting was set to 2 months, the file created on Monday and deleted on Friday would be preserved when the layers for that week were merged. The file exists as a special "deleted" item in the layer. Use the View > Show Deleted Items command to see and recall deleted items.

    Deleted items are purged naturally as part of a subsequent merge or by a compact action. The compact action seeks out deleted items that are now past their "keep" date (two months, in the previous example) and removes them, without merging any layers.

    To sort-of answer your second question, use the "Keep deleted items..." setting to enforce a grace period in which you can still recall the last captured version of a deleted item.

    Other Reasons

    The special "Delete Item(s)" command will delete any arbitrary item (file, folder, volume) from all layers of an archive, as if that item had never existed. This is mostly for cases where you have a very large file occupying space in the archive and you have no interest in keeping it, but don't want to sacrifice any other items or layers.

    For completeness, I should mention that all of the file deletion logic only applies to captured items. If you create a file, immediately delete it, and then perform a capture, the file will never be captured and its fate is outside QRecall's purview.

    - QRecall Development -
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