What is using Oracle database space? ("ORA-12953: ... exceeds the maximum allowed database size")
I assume from the error that you are using the express edition of the database.
SELECT owner, segment_name, segment_type, sum(bytes)/1024/1024 size_in_mb FROM dba_segments WHERE owner NOT IN ('SYS','SYSTEM') GROUP BY owner, segment_name, segment_type ORDER BY SUM(bytes)/1024/1024will show you the size of the objects owned by users other than SYS and SYSTEM ordered by their size in MB.
There are several DBA views, which look at several different aspects of "space":
* dba_free_space* dba_data_files* dba_tablespacesHere are several simple - and useful - scripts:
I would definitely look at these scripts: