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Editor to share with you how to use the Recycle Bin recycle bin in the database, I believe most people do not know much about it, so share this article for your reference, I hope you can learn a lot after reading this article, let's go to know it!

In principle, the Recycle Bin (Recycle Bin) is a data dictionary table that places database object information drop by the user. The object deleted by the user has not been deleted by the database and will still take up space. Unless it is due to manual Purge by the user or cleared by the database because there is not enough storage space.

In the Oracle 10g database, a recycle bin (Recycle Bin) database object was introduced.

The Recycle Bin, as its name implies, is the storage of deleted things. In principle, it is a data dictionary table that places the database object information deleted by the user (drop). The object deleted by the user has not been deleted by the database and will still take up space. Unless it is due to manual Purge by the user or cleared by the database because there is not enough storage space. With such a function, the database can reduce a lot of unnecessary trouble.

If a table is deleted, objects associated with the table, such as indexes, constraints, and other dependent objects, are prefixed with the bin$$.

I. start and shut down

You can use the following query statement to view the current status of the Recycle Bin:

SQL > SHOW PARAMETER RECYCLEBIN

NAME TYPE VALUE

Recyclebin string ON

Or

SQL > SELECT NAME, VALUE FROM V$PARAMETER WHERE NAME='recyclebin'

NAME VALUE

--

Recyclebin on

A return value of "on" indicates that the Recycle Bin is started, and "off" indicates that it is closed.

Of course, you can start or close each session (session) and system (system) in the Recycle Bin as follows:

ALTER SYSTEM SET recyclebin = ON

ALTER SESSION SET recyclebin = ON

ALTER SYSTEM SET recyclebin = OFF

ALTER SESSION SET recyclebin = OFF

Second, get the contents of the Recycle Bin

You can use any of the following statements to get the objects in the Recycle Bin:

SELECT * FROM RECYCLEBIN

SELECT * FROM USER_RECYCLEBIN

SELECT * FROM DBA_RECYCLEBIN

Third, restore

You can restore deleted objects using the following syntax:

FLASHBACK TABLE TO BEFORE DROP RENAME TO

Note: RENAME here is an optional command to rename deleted objects.

4. Empty the Recycle Bin

The emptying here includes two situations: first, you can clear it conditionally; second, you can empty it all. Let's first take a look at how conditional emptying can be done:

a. Clear a specific table:

PURGE TABLE

b. Clear a specific index:

PURGE INDEX

c. Clear the objects associated with the tablespace:

PURGE TABLESPACE

d. Clear a specific user's tablespace object:

PURGE TABLESPACE USER

e. Empty the Recycle Bin: (RECYCLEBIN is synonymous with USER_RECYCLEBIN)

PURGE RECYCLEBIN

f. When a table is drop, it is emptied directly from the Recycle Bin.

DROP TABLE PURGE

5. Query recyclebin information of the Recycle Bin

Set lines 200

Col owner for a15

Col object_name for a30

Col original_name for a30

Col operation for a9

Col type for a8

Col droptime for a19

Col ts_name for a15

Select owner,object_name, original_name, operation, type, droptime, ts_name

From dba_recyclebin

The above is all the contents of the article "how to use the Recycle Bin recycle bin in the Database". Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!

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