You can speedup a process if you have enough RAM to keep the database and uncompressed text copy in RAM, see example: Used_serial.db malformed - #4 by Alexey
Or if you do not mind to lose the statistic - you can use this instruction for each corrupted database: https://support.storj.io/hc/en-us/articles/4403032417044-How-to-fix-database-file-is-not-a-database-error