I had tt-rss on MySQL several years and did MySQL backups with self-made script, running with crontab every week. I migrated to PostgreSQL month and also migrated my database using your data_migration script. After successful migration I compared size of PostgreSQL dump and MySQL dump. My latest mysql_dump.sql.gz was 111 MB. postgresql_dump.sql.gz is 213 MB. Is it normal, that the size of postgresql dump is 2 times larger than mysql dump?