How to get the Schema/User size

In SQLPLUS run any of the following scripts to find the total size occupied by a particular schema.


1.

SQL> SELECT sum(bytes)/1024/1024 FROM user_segments;


The output above query would be similar as follows:


SUM(BYTES)/1024/1024
——————–
2552.75


-- OR --

2.

SQL> SELECT tablespace_name, Sum(bytes)/1024/1024 AS total_size_mb
FROM dba_segments
WHERE owner = Upper(&User_Name)
GROUP BY owner, rollup(tablespace_name)


-- OR --

3. To be more precise on particular table which excluding index,lob segments etc

SQL> SELECT sum(bytes)/1024/1024/1024 as size_gig, segment_type
FROM dba_segments
WHERE owner='XXX'
GROUP BY segment_type;