Interleaved deltas, or SCCS weave is a method used by the Source Code Control System to store all revisions of a file.
In order to extract a specific revision, an array of structures needs to be constructed, telling whether a specific block, tagged by a serial number in the interleaved deltas, will be copied to the output or not.
100 bytes of storage for each different serial number in the deltas in order to know how to extract a specific revision.
A SCCS history file with one million deltas would thus need 100 MB of virtual memory to unpack.
The advantages of the weave method are the following: Bazaar intended to use interleaved deltas in 2006,[5] but it was ditched due to poor performance after it was actually implemented in bzr 0.1.