Snapshot Sequence

An ordered list of all complete system states
Snapshot Sequence

How does it work?

Like event sourcing, this structure captures the history of a system. But rather than storing changes, snapshot sequence stores complete states. But as the state of a database or filesystem is formed by its entire contents, a naive implementation would quickly become very large. A smarter implementation creates each state as a set of hierarchical references to the underlaying data.

The term "snapshot" is well-known, but the data structure of linked snapshots doesn't have a name as far as I can tell, so I just named it "Snapshot sequence" myself.

It can be sufficient to only keep the previous complete state, or a few previous states.


  • Git stores its data as shapshots
  • React stores its data as a series of snapshots

When should you use it?

  • When you need to access a previous state very quickly.


  • It can be very hard to find an efficient implementation of a snapshot