DATAFILE FREE SIZE

Friends, Many a times we will be requiring to resize a datafile. For suppose, we have a tablespace with 3 datafiles with equal size. Then how we would be knowing which datafile to increase?? It is based on free space in a datafile. So, the below script will provide the info of how much free space is left in each datafile for a tablespace



SELECT SUBSTR (df.NAME, 1, 40) file_name,dfs.tablespace_name, df.bytes / 1024 / 1024 allocated_mb,
((df.bytes / 1024 / 1024) – NVL (SUM (dfs.bytes) / 1024 / 1024, 0))
used_mb,
NVL (SUM (dfs.bytes) / 1024 / 1024, 0) free_space_mb
FROM v$datafile df, dba_free_space dfs
WHERE df.file# = dfs.file_id(+)
GROUP BY dfs.file_id, df.NAME, df.file#, df.bytes,dfs.tablespace_name
ORDER BY file_name;