How to check tablespace and Datafile free size in oracle

How to check Datafile size for the single tablespace.

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 SELECT B.TABLESPACE_NAME,

         B.FILE_NAME,

         ROUND (B.BYTES / 1024 / 1024 / 1024, 2) "SIZE GB",

         ROUND (B.MAXBYTES / 1024 / 1024 / 1024, 2) "MAX SIZE GB",

         ROUND (SUM (A.BYTES) / 1024 / 1024 / 1024, 2) "FREE SPACE GB",

         CASE

            WHEN MAXBYTES = 0

            THEN

               ROUND (SUM (A.BYTES) / 1024 / 1024 / 1024, 2)

            ELSE

               ROUND (

                    ( (B.MAXBYTES - B.BYTES) + SUM (A.BYTES)) / 1024 / 1024 / 1024, 2)

         END

            "TOTAL FREE SPACE GB"

    FROM DBA_FREE_SPACE A, DBA_DATA_FILES B

   WHERE A.FILE_ID = B.FILE_ID AND B.TABLESPACE_NAME IN ('APPS_TS_MEDIA')

GROUP BY B.TABLESPACE_NAME,

         B.FILE_NAME,

         B.BYTES,

         B.MAXBYTES

ORDER BY 1, 2;

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2.  How to check tablespace Total size, used and free

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select

   fs.tablespace_name                          "Tablespace",

   (df.totalspace - fs.freespace)              "Used MB",

   fs.freespace                                "Free MB",

   df.totalspace                               "Total MB",

   round(100 * (fs.freespace / df.totalspace)) "Pct. Free"

from

   (select

      tablespace_name,

      round(sum(bytes) / 1048576) TotalSpace

   from

      dba_data_files

   group by

      tablespace_name

   ) df,

   (select

      tablespace_name,

      round(sum(bytes) / 1048576) FreeSpace

   from

      dba_free_space

   group by

      tablespace_name

   ) fs

where

   df.tablespace_name = fs.tablespace_name;