Managing versions of objects resulting from appending data for space efficiency

A computer program product for retaining versions of an object, wherein the computer program product comprises a computer readable storage medium having program instructions executable by a processor to cause operations, the operations comprising:

• appending changes to a previous version object resulting in a current version object, wherein the current version object includes version object data for versions of the object up to a current version number and the previous version object including version object data for versions of the object up through a previous version number prior to the current version number, wherein the current version object includes the version object data in the previous version object;
• updating version metadata for the previous version object to indicate an offset in the current version object at which the previous version object is located in current version object and including trailing metadata at an end of the previous version object before the changes were appended to the previous version object to create the current version object;
• deleting the previous version object after the appending changes to the previous version object;
• and
• retaining the version metadata for the previous version object after the previous version object is deleted, wherein the offset and the trailing metadata in the version metadata are used to recover the previous version object from the current version object with the trailing metadata restored in the recovered previous version object.

A system for retaining versions of an object, comprising:

• a processor;
• and
• a computer readable storage medium having program instructions that when executed by the processor cause operations, the operations comprising:
• maintaining a current version object including version object data for versions of the object up to a current version number and previous version object including version object data for versions of the object up through a previous version number prior to the current version number, wherein the current version object includes the version object data in the previous version object;
• updating version metadata for the previous version object to indicate an offset in the current version object from which the previous version object can be recovered;
• deleting the previous version object;
• and
• recovering the deleted previous version object from the offset in the current version object, indicated in the version metadata for the deleted previous version object.

A system for retaining versions of an object, comprising:

• a processor;
• and
• a computer readable storage medium having program instructions that when executed by the processor cause operations, the operations comprising:
• appending changes to a previous version object resulting in a current version object, wherein the current version object includes version object data for versions of the object up to a current version number and the previous version object including version object data for versions of the object up through a previous version number prior to the current version number, wherein the current version object includes the version object data in the previous version object;
• updating version metadata for the previous version object to indicate an offset in the current version object at which the previous version object is located in the current version object and including trailing metadata at an end of the previous version object before the changes were appended to the previous version object to create the current version object;
• deleting the previous version object after the appending changes to the previous version object;
• and
• retaining the version metadata for the previous version object after the previous version object is deleted, wherein the offset and the trailing metadata in the version metadata are used to recover the previous version object from the current version object with the trailing metadata restored in the recovered previous version object.

A method for retaining versions of an object, comprising:

• maintaining a current version object including version object data for versions of the object up to a current version number and previous version object including version object data for versions of the object up through a previous version number prior to the current version number, wherein the current version object includes the version object data in the previous version object;
• updating version metadata for the previous version object indicating an offset in the current version object from which the previous version object can be recovered;
• deleting the previous version object;
• and
• recovering the deleted previous version object from the offset in the current version object, indicated in the version metadata for the deleted previous version object.