Restoring Individual Tables

With Percona XtraBackup, you can export individual tables from any InnoDB database, and import them into Percona Server for MySQL with XtraDB or MySQL 8.0. (The source doesn’t have to be XtraDB or MySQL 8.0, but the destination does.) This only works on individual .ibd files, and cannot export a table that is not contained in its own .ibd file.

Let’s see how to export and import the following table:

CREATE TABLE export_test (
a int(11) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

Exporting the Table

This table should be created in innodb_file_per_table mode, so after taking a backup as usual with --backup, the .ibd file should exist in the target directory:

$ find /data/backups/mysql/ -name export_test.*
/data/backups/mysql/test/export_test.ibd

when you prepare the backup, add the extra parameter --export to the command. Here is an example:

$ xtrabackup --prepare --export --target-dir=/data/backups/mysql/

Note

If you’re trying to restore encrypted InnoDB tablespace table you’ll need to specify the keyring file as well:

$ xtrabackup --prepare --export --target-dir=/tmp/table \
--keyring-file-data=/var/lib/mysql-keyring/keyring

Now you should see a .exp file in the target directory:

$ find /data/backups/mysql/ -name export_test.*
/data/backups/mysql/test/export_test.exp
/data/backups/mysql/test/export_test.ibd
/data/backups/mysql/test/export_test.cfg

These three files are all you need to import the table into a server running Percona Server for MySQL with XtraDB or MySQL 8.0. In case server is using InnoDB Tablespace Encryption additional .cfp file be listed for encrypted tables.

Note

MySQL uses .cfg file which contains InnoDB dictionary dump in special format. This format is different from the .exp` one which is used in XtraDB for the same purpose. Strictly speaking, a .cfg` file is not required to import a tablespace to MySQL 8.0 or Percona Server for MySQL 8.0. A tablespace will be imported successfully even if it is from another server, but InnoDB will do schema validation if the corresponding .cfg file is present in the same directory.

Importing the Table

On the destination server running Percona Server for MySQL with XtraDB and innodb_import_table_from_xtrabackup option enabled, or MySQL 8.0, create a table with the same structure, and then perform the following steps:

  1. Run the ALTER TABLE test.export_test DISCARD TABLESPACE; command. If you see this error then you must enable innodb_file_per_table and create the table again.

    Error

    ERROR 1030 (HY000): Got error -1 from storage engine

  2. Copy the exported files to the test/ subdirectory of the destination server’s data directory

  3. Run ALTER TABLE test.export_test IMPORT TABLESPACE;

The table should now be imported, and you should be able to SELECT from it and see the imported data.