Does TencentDB for MariaDB support real-time backup?

Currently, real-time backup is not supported.

How does TencentDB for MariaDB decompress a backup and restore it to a self-built instance?

For more information, please see Restoring Instances from Backup Files.

What are the backup modes supported by TencentDB for MariaDB?

TencentDB for MariaDB supports full backup and incremental backup. For more information, please see Backup Mode.

How do I decompress backup and log files of TencentDB for MariaDB?

Backup files and log files (binlog files) of TencentDB for MariaDB are compressed with LZ4 (Extremely Fast Compression algorithm). You can use LZ4 for decompression.
For more information, please see Decompressing Backups and Logs.