Zabbix

SELECT json_object_agg(datname, row_to_json(T)) FROM (

    SELECT datname,

            numbackends,

            xact_commit,

            xact_rollback,

            blks_read,

            blks_hit,

            tup_returned,

            tup_fetched,

            tup_inserted,

            tup_updated,

            tup_deleted,

            conflicts,

            temp_files,

            temp_bytes,

            deadlocks

    FROM pg_stat_database where datname is not null) T