Storage format

These formats are private to MiniQdrant and intentionally incompatible with Qdrant.

Collection root

collection/
├── collection.json
├── CURRENT
├── manifest-000000000000000000NN.json
├── wal/00000000000000000001.wal
└── segments/seg-<uuid>/
    ├── meta.json
    ├── points.bin
    ├── payloads.bin
    ├── versions.bin
    ├── deleted.bin
    ├── hnsw.bin
    └── payload-indexes.bin

collection.json stores the immutable collection configuration and payload index schemas. CURRENT contains one manifest filename. Manifests are canonical JSON envelopes with a SHA-256 of their payload, generation, schema fingerprint, ordered segment IDs, and WAL replay boundary.

WAL frame

All integers are big-endian:

magic "MQWL" (4)
format version (1)
body length (4)
sequence (8)
operation kind (1)
canonical JSON operation payload (N)
CRC32 of body (4)

Operation kind 1 is a batch upsert and kind 2 is a batch delete. Sequences must start at one and remain contiguous. Recovery may truncate only an incomplete or checksum-invalid final frame.

Segment blobs

Each .bin file is independently framed:

magic "MQSG" (4)
format version (1)
JSON payload length (4)
canonical JSON payload (N)
CRC32 of header plus payload (4)

meta.json records the schema, indexed flag, and SHA-256 for every blob. Point IDs are explicitly tagged as integer or UUID. Versions and tombstones are separate logical columns. The current implementation reconstructs in-memory indexes from this semantic image when opening.

Snapshot

snapshot/
├── snapshot.json
└── collection/

snapshot.json maps every relative collection file to SHA-256. Creation copies the current manifest, referenced segments, metadata, CURRENT, and WAL into a temporary root, fsyncs it, then renames it. Restore checks the exact file set and hashes, validates manifest/segments, copies to a staging collection, rewrites only the collection name when requested, opens it successfully, and then publishes it.