How do I reclaim unused spaces in Oracle tablespace?

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After the data is pruned the datafiles contain unused space that needs to be reclaimed….If the datafile name must remain the same do the following:

Create a new tablespace.
Move the segments to the new tablespace.
Resize the original datafile.
Move the segments back to the original tablespace.
Drop the new tablespace.

How do you release the free space after delete in Oracle?

Reclaim Space After Deleting Data in Tables

Table Size: select bytes/1024/1024/1024 from dba_segments where segment_name like ‘%IBE_CT_RELATED_ITEMS%’;
29.8336.
Database Size: select.
1658.619.
Truncate the table: SQL> Truncate table IBE.
Shrink the table: SQL> alter table IBE.
Rebuild indexes:
Deallocate unused Space.

Does Oracle reuse deleted space?

Space is effectively reused when you delete. Your database will not show any new free space in dba_free_space — it will have more blocks on freelists and more empty holes in index structures. Now, as for the purge issues — the best strategy really lies in Oracle8i with partitions.

How do I delete unused columns in Oracle?

There’s another way to delete a column called logical delete, which sets the column as unused and you can delete it later. To set a column as unused: ALTER TABLE table_name SET UNUSED COLUMN column_name; After executing this command, the column will not be accessible anymore.

How do I free up disk space in Oracle?

Free Up Disk Space

Log in as the oracle user.
Find and remove the dump files. Copy. find . – name OCSDMDW_Dump*.dmp | xargs rm –rf.

How do I increase the size of my tablespace?

Increase the size of the tablespace If you haven’t turned on the autoextend feature and want to resize the tablespace, then do the following: For bigfile tablespaces: Resize the tablespace using the ALTER TABLESPACE command. You can specify the size in kilobytes (K), megabytes (M), gigabytes (G), or terabytes (T).

Does delete free the tablespace?

In Oracle, deleting data does not automatically reclaim disk space. The database will retain its storage until you do something administrative to the tablespace.

How do I clean up tablespace?

First, specify the name of the tablespace that you want to drop after the DROP TABLESPACE keywords. Second, use the INCLUDE CONTENTS to delete all contents of the tablespace. If the tablespace has any objects, you must use this option to remove the tablespace.

How do I get rid of unused columns?

Display the count for the unused columns. Select the information after setting the columns to unused. 9 rows selected. Drop the columns set as unused.

What is unused column Oracle?

Oracle provides an option to mark a column as UNUSED before you DROP, and do ALTER TABLE … DROP UNUSED COLUMNS at a later time. Once you mark a column as UNUSED, there is no going back to undo the action. So, marking it INVISIBLE before drop is a good idea.

How do I increase the size of my tablespace in Oracle?

and Tom said…

alter tablespace table_space_name add datafile ‘/path/to/some/file. dbf’ size Xm;
alter database datafile ‘/path/to/some/existing/file. dbf’ resize Xm;
alter database datafile ‘/path/to/some/existing/file. dbf’ autoextend on next Xm maxsize Ym;

How do I extend the tablespace overflow in Oracle?

Extend a tablespace in one of the following ways:

Add a data file to the tablespace. Use this method when either of the following conditions applies:
Set the AUTOEXTEND option for the data files in the tablespace.
Resize an existing data file to provide more space.

What does deallocate unused space mean in Oracle?

Deallocate unused space. Oracle notes that the “deallocate unused space” clause is used to to explicitly deallocate unused space at “the end” of a segment and makes that space available for other segments within the tablespace.

What is the difference between coalesce and deallocate unused space?

Answer: Both the coalesce and “deallocate unused space” commands serve to free-up space, but they do it in different ways: Oracle notes that the “deallocate unused space” clause is used to to explicitly deallocate unused space at “the end” of a segment and makes that space available for other segments within the tablespace.

What’s new in Oracle Database 10g for administrators?

This is an excerpt from “Oracle 10g New Features for Administrators” by Ahmed Baraka. In Oracle Database 10g, you can use the new segment shrinking capability to make sparsely populated segments give their space back to their parent tablespace. • You can only shrink segments that use Automatic Segment Space Management.

How to shrink segments in Oracle 10g?

In Oracle Database 10g, you can use the new segment shrinking capability to make sparsely populated segments give their space back to their parent tablespace. • You can only shrink segments that use Automatic Segment Space Management. • You must enable row movement for heap-organized segments.