Backup & Export

PocketDB provides hot backup and JSON export/import utilities.

Installation

Add PocketDB to your Cargo.toml:

[dependencies]
pocketdb = "0.1"

Or via the command line:

cargo add pocketdb

Hot Backup

Create a consistent backup of the database while it's running:

use pocketdb::Database;

let db = Database::open("mydata.pdb")?;

// Create a hot backup
db.backup_to("mydata_backup.pdb")?;

The backup is a byte-for-byte copy of the database file, consistent at the time of the copy.

JSON Export

Export a collection's documents to a JSON file:

db.export_collection_json("users", "users_export.json")?;

The output is a JSON array of documents:

[
  {
    "_id": "507f1f77bcf86cd799439011",
    "name": "Alice",
    "age": 30,
    "email": "alice@example.com"
  },
  {
    "_id": "507f1f77bcf86cd799439012",
    "name": "Bob",
    "age": 25,
    "email": "bob@example.com"
  }
]

JSON Import

Import documents from a JSON array into a collection:

let count = db.import_collection_json("users", "users_import.json")?;
println!("Imported {} documents", count);

The import reads a JSON array and creates documents from each element. The _id field is preserved if present; otherwise a new ObjectId is generated.

Complete Backup Example

use pocketdb::{Database, doc};

fn main() -> pocketdb::Result<()> {
    let db = Database::open("production.pdb")?;

    // Hot backup (binary copy)
    db.backup_to("production_backup.pdb")?;

    // Export all collections as JSON
    for name in db.list_collections() {
        let filename = format!("{}_export.json", name);
        db.export_collection_json(&name, &filename)?;
        println!("Exported {} to {}", name, filename);
    }

    Ok(())
}

Restore from Backup

From Binary Backup

// Simply open the backup file
let db = Database::open("production_backup.pdb")?;

From JSON Import

let db = Database::open("restored.pdb")?;

// Import each collection
let count = db.import_collection_json("users", "users_export.json")?;
println!("Restored {} users", count);

Repair and Cleanup

Validate Integrity

let db = Database::open("mydata.pdb")?;
if !db.validate()? {
    eprintln!("Corruption detected");
}

Repair Corrupted Database

// Static method — works even if the database can't be opened
let corrupted = Database::repair("mydata.pdb")?;

Clean Up Orphaned Files

If you delete a .pdb file but the .pocketdb/ directory still has WAL files:

// Returns true if cleanup was performed
Database::cleanup_orphaned("mydata.pdb")?;

Compact

let db = Database::open("mydata.pdb")?;
db.compact()?; // Flushes data and cleans WAL

Best Practices

1. Regular backups — schedule hot backups during low-traffic periods
2. Test restores — periodically verify backups can be restored
3. Keep multiple backups — maintain rolling backups for point-in-time recovery
4. Export before migrating — use JSON export as a safety net before schema changes
5. Monitor file size — check db.stats().file_size to plan storage
6. Validate after crashes — use db.validate() to check integrity