Users tablespace - datafile is 24.5 GB, only 1.2Gb used - What should I Do?

Question

Hi All,
In my database I have users tablespace and its datafile is users01.dbf. File size is 24.5 GB, but used data is 1.2 GB. I got this information from OEM, see below image:
https://picasaweb.google.com/100555146235257804098/Oracle_a1#5759303022195932370
How can I free the unused 23GB space?
Just to let you know about my background knowledge, I am an OBI report developer.
Thanks!

Answer 1

Just in case if this also helps.
I got a query to find the free space from
SELECT /* + RULE */ df.tablespace_name "Tablespace",
df.bytes / (1024 * 1024) "Size (MB)",
SUM(fs.bytes) / (1024 * 1024) "Free (MB)",
Nvl(Round(SUM(fs.bytes) * 100 / df.bytes),1) "% Free",
Round((df.bytes - SUM(fs.bytes)) * 100 / df.bytes) "% Used"
FROM dba_free_space fs,
(SELECT tablespace_name,SUM(bytes) bytes
FROM dba_data_files
GROUP BY tablespace_name) df
WHERE fs.tablespace_name (+) = df.tablespace_name
GROUP BY df.tablespace_name,df.bytes
UNION ALL
SELECT /* + RULE */ df.tablespace_name tspace,
fs.bytes / (1024 * 1024),
SUM(df.bytes_free) / (1024 * 1024),
Nvl(Round((SUM(fs.bytes) - df.bytes_used) * 100 / fs.bytes), 1),
Round((SUM(fs.bytes) - df.bytes_free) * 100 / fs.bytes)
FROM dba_temp_files fs,
(SELECT tablespace_name,bytes_free,bytes_used
FROM v$temp_space_header
GROUP BY tablespace_name,bytes_free,bytes_used) df
WHERE fs.tablespace_name (+) = df.tablespace_name
GROUP BY df.tablespace_name,fs.bytes,df.bytes_free,df.bytes_used
ORDER BY 4 DESC;
Results are:
TABLESPACE SIZE(MB) FREE(MB) %FREE %USED
USERS     24544.1875     23344.25     95     5
UNDOTBS1     965     878.25     91     9
EXAMPLE     100     21.6875     22     78
SYSAUX     828.8125     48.1875     6     94
SYSTEM     760     6.3125     1     99
TEMP     1315     0     0     100
thanks for your time let me know if you need any other information.