Storage & Snapshots

Patchforge writes schema snapshots to disk to support deterministic rollback. Snapshot data is never stored in the database.

What Is Stored

• Table data for selected tables
• Absence markers for non-existing tables
• Per-patch snapshot directories

Patch source SQL is never persisted. It is always pulled fresh from Git.

Snapshot Location

By default, snapshots are written to:

/tmp/patch-snapshots
    

The location can be overridden using:

SNAPSHOT_DIR=/data/snapshots
    

Kubernetes

In Kubernetes environments, SNAPSHOT_DIR must be backed by a PersistentVolumeClaim.

Patchforge must run as a single replica.

Retention

Patchforge does not automatically prune snapshots.

• No time-based cleanup
• No size-based cleanup
• No automatic compaction

Snapshot retention is an operational responsibility.

Rollback Status

Rollback functionality is currently considered beta.

Snapshot format and guarantees may evolve in future releases.

Failure Scenarios

If snapshot storage is unavailable:

• Schema patches will fail before execution
• No partial application occurs
• The database remains unchanged

Patchforge fails safe.