REDSHIFTのディスク容量（使用量、空き容量）を取得するSQL

SELECT
SUM(capacity)/1024 AS capacity_gbytes,
SUM(used)/1024 AS used_gbytes,
(SUM(capacity) - SUM(used))/1024 AS free_gbytes,
CAST(
CAST(SUM(used)/1024 AS DOUBLE PRECISION) / CAST(SUM(capacity)/1024 AS DOUBLE PRECISION)
AS DECIMAL(5,3)
) AS used_percentage
FROM
stv_partitions
WHERE
part_begin = 0;