How to clean table spaces of oracle

Oracle tablespace cleaning steps: 1. Identify unused tablespaces; 2. Delete unused segments; 3. Rebuild indexes; 4. Shrink tablespaces; 5. Merge tablespaces (if required); 6. Move data files (if required).

Oracle's steps to clean tablespaces

Oracle tablespaces are logical storage units used to store data in databases. Over time, the tablespace accumulates unused space, resulting in performance degradation. Regular table space cleaning is essential to keep your database efficient.

step:

1. Identify tablespaces that need to be cleaned

Use the following query to identify unused tablespaces:

 <code>SELECT tablespace_name, SUM(bytes) / 1024 / 1024 / 1024 AS GB_USED FROM dba_segments GROUP BY tablespace_name ORDER BY GB_USED DESC;</code>

2. Delete unused segments

Use the following query to find out the segment that takes up unused space:

 <code>SELECT owner, segment_name, segment_type, bytes FROM dba_segments WHERE tablespace_name = '' AND bytes </code>

Then, delete the segments using the following command:

 <code>DROP TABLE . PURGE;</code>

3. Rebuild the index

Rebuilding the index helps reclaim unused space from the tablespace:

 <code>ALTER INDEX  REBUILD;</code>

4. Shrink the table space

Shrinking the tablespace will free up unused space, thereby reducing its size:

 <code>ALTER TABLESPACE  SHRINK;</code>

5. Merge tablespaces

If you have multiple small tablespaces, consider merging them into a larger tablespace:

 <code>ALTER TABLESPACE  ADD DATAFILE '';</code>

6. Move data files

If there is a lot of unused space in the tablespace, consider moving the data file to another location:

 <code>ALTER DATABASE DATAFILE '' MOVE ''</code>

By following these steps, Oracle tablespaces can be effectively cleaned, unused space can be freed and database performance can be improved.

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