Increasing tablespace in size

 I am looking to add space to a tablespace that is about 90% full.

I the query below to retrieve the tablespace block size:

SELECT BLOCK_SIZE FROM DBA_TABLESPACES WHERE TABLESPACE_NAME='TEST';

Based on the query above, the block size is 8K, so the max datafile size is 32GB. So then I can increase the file size of one of the datafiles.

In order to check on datafiles I use:

SELECT df.FILE_NAME, df.BYTES/1024/1024 AS file_size_MB, df.BYTES/(1024*1024*1024) AS file_size_GB, SUM(fs.BYTES)/1024/1024 AS free_space_MB
FROM dba_data_files df
JOIN dba_free_space fs USING(FILE_ID)