SELECT
	all_columns.table_schema,
	schema_info.schema_description,
	all_columns.table_name,
	table_info.table_description AS table_description,
	all_columns.column_name,
	all_columns.data_type,
	columns_info.description AS column_description
FROM
	information_schema.columns AS all_columns
LEFT JOIN (
	SELECT
		*
	FROM
		pg_catalog.pg_statio_all_tables AS st
	LEFT JOIN pg_catalog.pg_description pgd 
		ON pgd.objoid = st.relid
	LEFT JOIN information_schema.columns AS c
		ON pgd.objsubid = c.ordinal_position
		AND c.table_schema = st.schemaname
		AND c.table_name = st.relname 
	) AS columns_info
		ON all_columns.table_schema = columns_info.schemaname
		AND all_columns.table_name = columns_info.relname
		AND columns_info.column_name = all_columns.column_name
LEFT JOIN (
	SELECT
		*,
		pg_catalog.obj_description(pgc.oid, 'pg_class') AS table_description
	FROM
		information_schema.tables AS t
	INNER JOIN pg_catalog.pg_class AS pgc 
		ON t.table_name = pgc.relname
	WHERE
		t.table_type = 'BASE TABLE'
		AND pg_catalog.obj_description(pgc.oid, 'pg_class') IS NOT NULL
	) AS table_info
		ON	
			table_info.table_name = all_columns.table_name
			AND table_info.table_schema = all_columns.table_schema
INNER JOIN (
	SELECT
		nspname,
		obj_description(oid) AS schema_description
	FROM
		pg_catalog.pg_namespace 
	) AS schema_info 
		ON schema_info.nspname = all_columns.table_schema
WHERE
	all_columns.table_schema != 'pg_catalog';

SELECT
	tables.database AS table_schema,
	tables.name AS table_name,
	columns.name AS column_name,
	TYPE AS data_type,
	columns.comment AS column_description,
	tables.comment AS table_description
FROM
	system.tables AS TABLES
LEFT JOIN system.columns 
	ON system.columns.table = system.tables.name