SQLite

SQLite is the local durable option when the application owns database files and can apply the repository's locking and journal-mode rules. Metadata and blocks may use separate database files or be paired with another provider.

Namespace {
  nodes[42] = NodeMetadata {
    stats: { ino: 42, size: 8192, mode: regular },
    data: File(FileLayout {
      chunker: { algorithm: "fixed-size", version: 1, chunk_size: 4096 },
      extents: [
        { file_offset: 0,    block: "b012...", block_offset: 0, length: 4096 },
        { file_offset: 4096, block: "bfed...", block_offset: 0, length: 4096 }
      ]
    })
  }
}

BlockId "b012..." -> [4 KiB raw bytes]
BlockId "bfed..."  -> [4 KiB raw bytes]

SELECT name, sql
FROM sqlite_master
WHERE type = 'table' AND name LIKE 'mount_rs_%'
ORDER BY name;

PRAGMA table_info(mount_rs_metadata);
PRAGMA table_info(mount_rs_blocks);
PRAGMA table_info(mount_rs_versions);

Layout and chunking

ChunkedFs records fixed-size chunk configuration in the namespace/file layout. A block row contains the opaque block ID and a BLOB; SQLite does not reinterpret the bytes as files or pages owned by the mount layer.

Durability and consistency

File-backed databases enable the provider's durable flag and use SQLite's synchronous=FULL setup plus provider-clock lease and revision checks. In-memory SQLite is volatile. SQLite used as a provider is different from hosting a separate SQLite database inside a native mount.

Across every split-store composition, new blocks are flushed before metadata references are published. A provider acknowledgement is not automatically a power-loss or distributed-locking guarantee.

Inspect metadata and blocks with sqlite3

sqlite3 metadata.sqlite <<'SQL'
SELECT id, revision, length(namespace) AS namespace_bytes
FROM mount_rs_metadata;
SELECT id, sequence, durable FROM mount_rs_versions
ORDER BY sequence DESC LIMIT 10;
SQL

sqlite3 blocks.sqlite   'SELECT id, length(bytes) AS block_bytes FROM mount_rs_blocks LIMIT 20;'

Credentials, cleanup, and safe operations

Close all filesystem handles before copying or deleting database files. Remove only databases owned by the volume; never delete block rows that a live metadata revision may still reference. SQLite has no network credentials in this provider path.

Current limits

The provider's file durability does not prove safe SQLite hosting over every transport. The verified Linux FUSE matrix and macOS single-host NFS DELETE-journal path do not establish universal WAL, power-loss, distributed-locking, or cross-platform guarantees.

← Back to providers