如何从备份文件恢复H2（内存型）数据库？

Absolutely—H2 does provide a corresponding command to restore backups created with the BACKUP command for nioMemFS file systems: the RESTORE command. Here's what you need to know to use it effectively:

Key Details About the RESTORE Command #

• Core Syntax: To restore a backup, run this SQL statement once you've connected to a nioMemFS database instance:

  RESTORE FROM '/path/to/your/backup-file.zip'
  

• Required Database Type: Just like the BACKUP command is restricted to nioMemFS, the RESTORE command only works with nioMemFS database instances (identified by URLs starting with jdbc:h2:nioMemFS:). You cannot use this backup file to restore a standard in-memory database (URL starting with jdbc:h2:mem:).
• Overwriting Existing Data: If the target nioMemFS database already contains data, H2 will throw an error by default. To overwrite existing data during restore, add the OVERWRITE clause:

  RESTORE FROM '/path/to/your/backup-file.zip' OVERWRITE
  

Step-by-Step Example #

1. First, create a nioMemFS database connection (this is where you'll restore the backup):

   jdbc:h2:nioMemFS:/restoredDB;DB_CLOSE_ON_EXIT=FALSE
   

2. Execute the restore command in your SQL client:

   RESTORE FROM '/var/backups/h2-nio-backup.zip' OVERWRITE
   

3. Verify the restore by querying your tables—your data should now be present in the nioMemFS instance.

Important Notes #

• Backup files created via BACKUP are automatically compressed as ZIP files, so you don't need to handle compression/decompression manually.
• Ensure the user running the H2 process has read access to the backup file path.

内容的提问来源于stack exchange，提问作者Michael