Prevent DDL Trigger:

DROP TRIGGER prevent_ddl_t;

CREATE OR REPLACE TRIGGER prevent_ddl_t
BEFORE ALTER OR DROP OR TRUNCATE
ON SCHEMA
BEGIN
RAISE_APPLICATION_ERROR(-20001,' You are not authorized to perform DDL.');
END;
/

Oracle DBA Scripts - Datafile related

How to check datafile size?

SELECT dp.tablespace_name

, df.file_name

, dp.block_size

, round(sum(df.maxbytes) /(1024*1024*1024),0) "Max_Size_GB"

, round(sum(df.bytes) /(1024*1024*1024),0) "Used_Size_GB"

FROM dba_tablespaces dp, dba_data_files df

WHERE dp.tablespace_name=df.tablespace_name

GROUP BY dp.tablespace_name, dp.block_size , df.file_name,df.maxbytes

ORDER BY dp.tablespace_name, df.file_name;