BACKUP keyword

Syntax

Description

Creates a backup for one, several, or all database tables.

Backup directory

tip

BACKUP TABLE requires a backup directory which is set using the configuration key cairo.sql.backup.root in the server.conf file.

Example configuration key

cairo.sql.backup.root=/Users/UserName/Desktop

The backup directory can be on a local disk to the server, on a remote disk, or a remote filesystem. QuestDB will enforce that the backup are only written in a location relative to the backup directory. This is a security feature to disallow random file access by QuestDB.

The tables will be written in a directory with today's date. By default, the format is yyyy-MM-dd, for example 2020-04-20.

tip

You can define a custom format using the cairo.sql.backup.dir.datetime.format configuration key like the example below

Example user-defined directory format

cairo.sql.backup.dir.datetime.format=yyyy-dd-MM

The data and meta files will be written following the db directory structure

Directory structure (single backup)

'backup directory/'

2020-04-20

├── table1

├── table2

└── ...

If a user performs several backups on the same date, each backup will be written a new directory. Subsequent backups on the same date will look as follows:

Directory structure (multiple backups)

'backup directory/'

├── 2020-04-20 'first'

├── 2020-04-20.1 'second'

├── 2020-04-20.2 'third'

├── 2020-04-21 'first new date'

├── 2020-04-21.1 'first new date'

└── ...

Examples

Single table

BACKUP TABLE table1;

Multiple tables

BACKUP TABLE table1, table2, table3;

All tables

BACKUP DATABASE;