@@ -19,3 +19,5 @@ Access cannot be managed at the cell level: rows and columns are the smallest un
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@@ -19,3 +19,5 @@ Access cannot be managed at the cell level: rows and columns are the smallest un
# Retention
# Retention
After data has been stored into a PEP cell, downloaders can retrieve that data from there. When new data are stored into the same cell, new downloads will receive the updated version instead. But the old data are never discarded: PEP retains a complete record of all data that has ever been stored into the system. This allows PEP to reconstruct its data set as it was at any time in the past. Such "snapshots" are intended to be made accessible to users for download (although the functionality has not yet been created). This allows the exact same data to be retrieved multiple times, which is usable e.g. for scientific replication studies.
After data has been stored into a PEP cell, downloaders can retrieve that data from there. When new data are stored into the same cell, new downloads will receive the updated version instead. But the old data are never discarded: PEP retains a complete record of all data that has ever been stored into the system. This allows PEP to reconstruct its data set as it was at any time in the past. Such "snapshots" are intended to be made accessible to users for download (although the functionality has not yet been created). This allows the exact same data to be retrieved multiple times, which is usable e.g. for scientific replication studies.
A similar policy applies to column management. When a Data Administrator removes a column, the data stored in that column is retained for future use. Therefore (once the feature is available) when users retrieve an older snapshot, they will also receive the data from the "removed" column. Data Administrators should be aware that, if they remove and then re-add a column with the same name, the newly created column will immediately contain the previously stored data.
