SQLite Reopen

This example writes graph records to SQLite, compacts adjacency data into a segment sidecar, reopens the database, and checks that indexes and snapshots still behave as expected.

Python

import json
from pathlib import Path
from tempfile import TemporaryDirectory
from tonggraph import Graph

with TemporaryDirectory() as tmp:
    db_path = Path(tmp) / "tonggraph.db"
    graph = Graph(str(db_path))
    source = graph.add_node("source", labels=["Entity"], properties={"name": "A"})
    target = graph.add_node("target", labels=["Entity"], properties={"name": "B"})
    graph.add_edge(source, target, "LINKS", properties={"probability": 0.75})

    snapshot = graph.snapshot()
    graph.compact()
    del graph

    reopened = Graph(str(db_path))
    result = {
        "source_id": source,
        "snapshot_node_count": snapshot.node_count(),
        "reopened_counts": {
            "nodes": reopened.node_count(),
            "edges": reopened.edge_count(),
        },
        "entity_nodes": reopened.nodes_with_label("Entity"),
        "links_neighbors": reopened.neighbors(source, edge_type="LINKS"),
        "segment_manifest_exists": Path(f"{db_path}.segments/manifest.txt").exists(),
    }

print(json.dumps(result, indent=2, sort_keys=True))

Output:

{
  "entity_nodes": [
    0,
    1
  ],
  "links_neighbors": [
    1
  ],
  "reopened_counts": {
    "edges": 1,
    "nodes": 2
  },
  "segment_manifest_exists": true,
  "snapshot_node_count": 2,
  "source_id": 0
}