Time Travel

• Cypher
• Python SDK

// Show commit history
CALL db.history()

// Read a previous commit
checkout c0a6ce3c0315be7a

// Query graph at specific commit
MATCH (n:Person)-[e:KNOWS]->(m:Person)
WHERE n.name = 'Jane'
AND m.name = 'John'
RETURN n, e, m

# Show commit history
client.query("CALL db.history()")

# Read a previous commit
client.checkout(change="main", commit="c0a6ce3c0315be7a")

# Query graph at specific commit
client.query("""
MATCH (n:Person)-[e:KNOWS]->(m:Person)
WHERE n.name = 'Jane'
AND m.name = 'John'
RETURN n, e, m
""")

​

About db.history()

• Commits are listed newest first, and the latest one is marked with a literal (HEAD) suffix on its hash: strip it before passing the hash to checkout.
• Every COMMIT and every submitted change adds an entry.
• nodeCount and edgeCount count what that commit added, not the graph totals.
• Use hashes exactly as printed (they are not zero-padded). An unknown hash returns COMMIT_NOT_FOUND from client.checkout(commit=...), and zeros from CALL db.describeCommit('<hash>').
• A past commit is read-only, so make writes on main or in a change. Call client.checkout() to return to main.

​

Lazy Commit Loading

TuringDB lazily loads commits from disk. When a graph is loaded, only the HEAD commit (the latest commit on the current branch) is fully loaded into memory. All other commits are registered but their data remains on disk until explicitly requested.

This means that to query a past commit, its data must first be loaded into memory using the LOAD COMMIT command:

LOAD COMMIT 'c0a6ce3c0315be7a'

​

Example: Querying a Past Commit via the REST API

// Step 1: Load the commit into memory
LOAD COMMIT 'be9643a1c03f8e2b'

// Step 2: Now you can query at that commit
MATCH (n:Person)-[e:KNOWS]->(m:Person)
RETURN n.name, m.name

LOAD COMMIT is idempotent — calling it on an already-loaded commit is a no-op and returns immediately.