How to Unlock the Locked Table in ORACLE

Oracle puts locks while performing any DDL or DML operation on oracle tables.When table locks is present on any tables in Oracle we cannot run DDL on those tables.

Some of the locks automatically set by oracle are RS and RX Locks.

SELECT … FOR UPDATE execution results in RS (row share) table lock. When you execute an INSERT, UPDATE or DELETE Oracle puts RX (row exclusive) table lock.

We have to kill the session which holds the lock in order to execute further operations. Follow the below steps to kill the session and forcibly unlock the table.

Let’s assume that 'EMP' table is locked,

How to Delete All Files In a Directory Except Few Files in LINUX /UNIX

First let’s go through the RM command in UNIX:

The rm command is used in Unix / Linux to remove a file or a directory. The syntax is as follows:

Syntax:

rm [OPTION] [FILE] 

OPTION’s include

> rm –f {file-name} – To remove files forcefully without prompting to the user.

> rm –i {file-name} – To remove files by prompting to the user for confirming.

> rm –r {file-name} – To remove files in directories recursively.

Now we will see how to delete All Files in Directory except Few files>

1) USING RM COMMAND:

To remove all files from directory /home/opt/class/ except .log and .zip

> rm /home/opt/class/ !(*.zip|*.log)

To remove all files except a specific file (file123)

> rm  !(file123)