Working with Databases

Database Methods

The following methods are available to manage databases via JavaScript. Please note that several of these methods can be used from the _system database only.

Name

return the database name db._name()

Returns the name of the current database as a string.

Examples

arangosh> require("@arangodb").db._name();

_system

ID

return the database id db._id()

Returns the id of the current database as a string.

Examples

arangosh> require("@arangodb").db._id();

1

Path

return the path to database files db._path()

Returns the filesystem path of the current database as a string.

Examples

arangosh> require("@arangodb").db._path();

/tmp/arangosh_FOcOhj/tmp-64-2156680287/rocksdb/data

isSystem

return the database type db._isSystem()

Returns whether the currently used database is the _system database. The system database has some special privileges and properties, for example, database management operations such as create or drop can only be executed from within this database. Additionally, the _system database itself cannot be dropped.

Use Database

change the current database db._useDatabase(name)

Changes the current database to the database specified by name. Note that the database specified by name must already exist.

Changing the database might be disallowed in some contexts, for example server-side actions (including Foxx).

When performing this command from arangosh, the current credentials (username and password) will be re-used. These credentials might not be valid to connect to the database specified by name. Additionally, the database only be accessed from certain endpoints only. In this case, switching the database might not work, and the connection / session should be closed and restarted with different username and password credentials and/or endpoint data.

List Databases

return the list of all existing databases db._databases()

Returns the list of all databases. This method can only be used from within the _system database.

Create Database

create a new database db._createDatabase(name, options, users)

Creates a new database with the name specified by name. There are restrictions for database names (see DatabaseNames).

Note that even if the database is created successfully, there will be no change into the current database to the new database. Changing the current database must explicitly be requested by using the db._useDatabase method.

The options attribute currently has no meaning and is reserved for future use.

The optional users attribute can be used to create initial users for the new database. If specified, it must be a list of user objects. Each user object can contain the following attributes:

• username: the user name as a string. This attribute is mandatory.
• passwd: the user password as a string. If not specified, then it defaults to an empty string.
• active: a boolean flag indicating whether the user account should be active or not. The default value is true.
• extra: an optional JSON object with extra user information. The data contained in extra will be stored for the user but not be interpreted further by ArangoDB.

If no initial users are specified, a default user root will be created with an empty string password. This ensures that the new database will be accessible via HTTP after it is created.

You can create users in a database if no initial user is specified. Switch into the new database (username and password must be identical to the current session) and add or modify users with the following commands.

  require("@arangodb/users").save(username, password, true);
  require("@arangodb/users").update(username, password, true);
  require("@arangodb/users").remove(username);

Alternatively, you can specify user data directly. For example:

  db._createDatabase("newDB", {}, [{ username: "newUser", passwd: "123456", active: true}])

Those methods can only be used from within the _system database.

Drop Database

drop an existing database db._dropDatabase(name)

Drops the database specified by name. The database specified by name must exist.

Note: Dropping databases is only possible from within the _system database. The _system database itself cannot be dropped.

Databases are dropped asynchronously, and will be physically removed if all clients have disconnected and references have been garbage-collected.

Engine

retrieve the storage engine type used by the server db._engine()

Returns the name of the storage engine in use (mmfiles or rocksdb), as well as a list of supported features (types of indexes and dfdb).

Engine statistics

retrieve statistics related to the storage engine (rocksdb) db._engineStats()

Returns some statistics related to the storage engine activity, including figures about data size, cache usage, etc.

Note: Currently this only produces useful output for the RocksDB engine.