Check the undo tablespace (Size in GB) in Oracle
SELECT
tablespace_name,
ROUND(SUM(bytes) / 1024 / 1024 / 1024, 2) AS total_size_gb,
ROUND(SUM(maxbytes) / 1024 / 1024 / 1024, 2) AS max_extend_size_gb
FROM dba_data_files
WHERE tablespace_name = (
SELECT value
FROM v$parameter
WHERE name = ‘undo_tablespace’)
GROUP BY tablespace_name;
