§2024-11-03

¶ Transfer data to other system

1. mongoexport

• Purpose: Used to export data from a MongoDB database to a JSON or CSV file.
• Usage: Typically used to create backups of collections or to transfer data to other systems.
• Example Command:
  • mongoexport --db myDatabase --collection myCollection --out myCollection.json
  • Options: You can specify query filters, fields to include, and other options to customize the export.

2. mongoimport
   • Purpose: Used to import data from a JSON or CSV file into a MongoDB database.
   • Usage: Often used for populating a database with initial data or updating existing collections.
   • Example Command:
     • mongoimport --db myDatabase --collection myCollection --file myCollection.json
     • Options: You can specify file format, unique key handling, and other parameters.

¶ Transfer data to the same mongoDB system

1. mongodump

• Purpose: Creates a binary backup of a MongoDB database.
• Usage: Used to create backups of the entire database or specific collections, preserving data types and indexes.
• Example Command:
  • mongodump --db myDatabase --out /backup/dump
  • Options: You can choose to dump specific collections or set compression options.

2. mongorestore

• Purpose: Restores a database from a binary dump created by mongodump.
• Usage: Used to restore data from backups, allowing you to recover databases or collections.
• Example Command:
  • mongorestore --db myDatabase /backup/dump/myDatabase
  • Options: You can specify whether to overwrite existing data, drop collections before restoring, and more.

¶Incremental Backups: ???

If you need to back up only changes made since the last backup, you may consider using oplog (if using replication) or perform periodic dumps rather than full dumps every time.

¶ mongosh