Drop User Cascade in Oracle


I will explain how to Drop User Cascade in Oracle in this post.


You can remove a database user and user’s objects with executing DROP USER command.

If you drop a user, Oracle removes and purges all of that user’s schema objects from the recycle bin.

DROP USER Syntax is as follows.

You can get the following error during the Drop User.


SQL>drop user MSD cascade;
drop user username cascade
ERROR at line 1:ORA-01940: cannot drop a user that is currently connected



To drop any user, you need to lock related user firstly.

SQL> alter USER MSD account lock;

User altered.


Then kill the session of related user as follows.

SQL> select s.sid, s.serial#, s.status, p.spid from gv$session s, gv$process p where s.username = 'MSD' and p.addr (+) = s.paddr;
——— ———- ——– ————
163 34 INACTIVE 342463
634 63 INACTIVE 153783




Kill these sessions as follows.

SQL> alter system kill session '163,263';
System altered.

SQL> alter system kill session '634,63';
System altered.


Now you can drop this user ( SCHEMA )

SQL> drop user MSD cascade;
User dropped.



Do you want to learn Oracle Priviliges, then read the following articles.

How to Grant and Revoke Privileges | Create and Drop any User in Oracle Database



Do you want to learn Oracle Database for Beginners, then read the following articles.


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About Mehmet Salih Deveci

I am Founder of SysDBASoft IT and IT Tutorial and Certified Expert about Oracle & SQL Server database, Goldengate, Exadata Machine, Oracle Database Appliance administrator with 10+years experience.I have OCA, OCP, OCE RAC Expert Certificates I have worked 100+ Banking, Insurance, Finance, Telco and etc. clients as a Consultant, Insource or Outsource.I have done 200+ Operations in this clients such as Exadata Installation & PoC & Migration & Upgrade, Oracle & SQL Server Database Upgrade, Oracle RAC Installation, SQL Server AlwaysOn Installation, Database Migration, Disaster Recovery, Backup Restore, Performance Tuning, Periodic Healthchecks.I have done 2000+ Table replication with Goldengate or SQL Server Replication tool for DWH Databases in many clients.If you need Oracle DBA, SQL Server DBA, APPS DBA,  Exadata, Goldengate, EBS Consultancy and Training you can send my email adress [email protected].-                                                                                                                                                                                                                                                 -Oracle DBA, SQL Server DBA, APPS DBA,  Exadata, Goldengate, EBS ve linux Danışmanlık ve Eğitim için  [email protected] a mail atabilirsiniz.

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