After pulling the latest Nextcloud image I got some warnings about missing indices, missing primary keys and about converting some column types to big int. The warnings could easily be fixed by running the suggested occ comands. Append “-no-interaction” to suppress the confirmation question (see docs).
docker exec --user www-data nextcloud-app php /var/www/html/occ db:add-missing-indices
docker exec --user www-data nextcloud-app php /var/www/html/occ db:add-missing-primary-keys
docker exec --user www-data nextcloud-app php /var/www/html/occ db:convert-filecache-bigint --no-interaction