how to find size of database, schema, table in redshift

Solution 1:

The above answers don't always give correct answers for table space used. AWS support have given this query to use:

SELECT   TRIM(pgdb.datname) AS Database,
         TRIM(a.name) AS Table,
         ((b.mbytes/part.total::decimal)*100)::decimal(5,2) AS pct_of_total,
         b.mbytes,
         b.unsorted_mbytes
FROM     stv_tbl_perm a
JOIN     pg_database AS pgdb
  ON     pgdb.oid = a.db_id
JOIN     ( SELECT   tbl,
                    SUM( DECODE(unsorted, 1, 1, 0)) AS unsorted_mbytes,
                    COUNT(*) AS mbytes
           FROM     stv_blocklist
           GROUP BY tbl ) AS b
       ON a.id = b.tbl
JOIN     ( SELECT SUM(capacity) AS total
           FROM   stv_partitions
           WHERE  part_begin = 0 ) AS part
      ON 1 = 1
WHERE    a.slice = 0
ORDER BY 4 desc, db_id, name;

Solution 2:

Yes, mbytes in your example is 372Mb. Here's what I've been using:

select
  cast(use2.usename as varchar(50)) as owner, 
  pgc.oid,
  trim(pgdb.datname) as Database,
  trim(pgn.nspname) as Schema,
  trim(a.name) as Table,
  b.mbytes,
  a.rows
from 
 (select db_id, id, name, sum(rows) as rows
  from stv_tbl_perm a
  group by db_id, id, name
  ) as a
 join pg_class as pgc on pgc.oid = a.id
 left join pg_user use2 on (pgc.relowner = use2.usesysid)
 join pg_namespace as pgn on pgn.oid = pgc.relnamespace 
    and pgn.nspowner > 1
 join pg_database as pgdb on pgdb.oid = a.db_id
 join 
   (select tbl, count(*) as mbytes
    from stv_blocklist
    group by tbl
   ) b on a.id = b.tbl
 order by mbytes desc, a.db_id, a.name; 

Solution 3:

I'm not sure about grouping by database and scheme, but here's a short way to get usage by table,

SELECT tbl, name, size_mb FROM
(
  SELECT tbl, count(*) AS size_mb
  FROM stv_blocklist
  GROUP BY tbl
)
LEFT JOIN
(select distinct id, name FROM stv_tbl_perm)
ON id = tbl
ORDER BY size_mb DESC
LIMIT 10;