Purging LOBs:
If we purge a table which contains LOBs , we may not reclaim space. BLOBs are stored out of line once they exceed 4,000 bytes (you can also specify that they are always stored out of line as well).
If the BLOBs were all inline, each taking 4000 or less bytes, then you did free space in your table. The table will not shrink in size (tables NEVER shrink) but it will have more blocks on its free list for subsequent inserts.
SQL> desc applsys.fnd_lobs
Name Null? Type
----------------------------------------- -------- ----------------------------
FILE_ID NOT NULL NUMBER
FILE_NAME VARCHAR2(256)
FILE_CONTENT_TYPE NOT NULL VARCHAR2(256)
FILE_DATA BLOB
UPLOAD_DATE DATE
EXPIRATION_DATE DATE
PROGRAM_NAME VARCHAR2(32)
PROGRAM_TAG VARCHAR2(32)
LANGUAGE VARCHAR2(4)
ORACLE_CHARSET VARCHAR2(30)
FILE_FORMAT NOT NULL VARCHAR2(10)
SQL> select round(sum(bytes)/1024/1024) Mb from dba_segments where segment_name='FND_LOBS';
MB
----------
179
SQL> select round(sum(bytes)/1024/1024) Mb from dba_segments where segment_name='SYS_LOB0000034032C00004$$';
MB
----------
20699
SQL> select OBJECT_NAME,OBJECT_ID,OWNER,OBJECT_TYPE,STATUS from dba_objects where object_name='SYS_LOB0000034032C00004$$' and object_type='LOB';
OBJECT_NAME
--------------------------------------------------------------------------------
OBJECT_ID OWNER OBJECT_TYPE STATUS
---------- ------------------------------ ------------------- -------
SYS_LOB0000034032C00004$$
34033 APPLSYS LOB VALID
SQL> select OWNER,TABLE_NAME,COLUMN_NAME,SEGMENT_NAME,TABLESPACE_NAME from dba_lobs where SEGMENT_NAME='SYS_LOB0000034032C00004$$';
OWNER TABLE_NAME
------------------------------ ------------------------------
COLUMN_NAME
--------------------------------------------------------------------------------
SEGMENT_NAME TABLESPACE_NAME
------------------------------ ------------------------------
APPLSYS FND_LOBS
FILE_DATA
SYS_LOB0000034032C00004$$ APPS_TS_MEDIA
Name Null? Type
----------------------------------------- -------- ----------------------------
FILE_ID NOT NULL NUMBER
FILE_NAME VARCHAR2(256)
FILE_CONTENT_TYPE NOT NULL VARCHAR2(256)
FILE_DATA BLOB
UPLOAD_DATE DATE
EXPIRATION_DATE DATE
PROGRAM_NAME VARCHAR2(32)
PROGRAM_TAG VARCHAR2(32)
LANGUAGE VARCHAR2(4)
ORACLE_CHARSET VARCHAR2(30)
FILE_FORMAT NOT NULL VARCHAR2(10)
SQL> select round(sum(bytes)/1024/1024) Mb from dba_segments where segment_name='FND_LOBS';
MB
----------
179
SQL> select round(sum(bytes)/1024/1024) Mb from dba_segments where segment_name='SYS_LOB0000034032C00004$$';
MB
----------
20699
SQL> select OBJECT_NAME,OBJECT_ID,OWNER,OBJECT_TYPE,STATUS from dba_objects where object_name='SYS_LOB0000034032C00004$$' and object_type='LOB';
OBJECT_NAME
--------------------------------------------------------------------------------
OBJECT_ID OWNER OBJECT_TYPE STATUS
---------- ------------------------------ ------------------- -------
SYS_LOB0000034032C00004$$
34033 APPLSYS LOB VALID
SQL> select OWNER,TABLE_NAME,COLUMN_NAME,SEGMENT_NAME,TABLESPACE_NAME from dba_lobs where SEGMENT_NAME='SYS_LOB0000034032C00004$$';
OWNER TABLE_NAME
------------------------------ ------------------------------
COLUMN_NAME
--------------------------------------------------------------------------------
SEGMENT_NAME TABLESPACE_NAME
------------------------------ ------------------------------
APPLSYS FND_LOBS
FILE_DATA
SYS_LOB0000034032C00004$$ APPS_TS_MEDIA
Action Plan
===========
1) Take hotbackup for the instance
2) Execute the following commands as sysdba
SQL> delete from APPLSYS.FND_LOBS
SQL> alter table applsys.FND_LOBS modify lob (FILE_DATA) (shrink space);
3) Then Execute the following commands to confirm the space gained.
SQL> select round(sum(bytes)/1024/1024) Mb from dba_segments where segment_name='FND_LOBS';
SQL> select round(sum(bytes)/1024/1024) Mb from dba_segments where segment_name='SYS_LOB0000034032C00004$$';
NOTE: It should return "0" for both the commands.
Or
Update the LOB column value with NULL and then execute the following command.
SQL> alter table applsys.FND_LOBS modify lob (FILE_DATA) (shrink space);
OR
Use the DBMS_LOB.ERASE package and erase the LOBs. Then execute the following command ..
SQL> alter table applsys.FND_LOBS modify lob (FILE_DATA) (shrink space);
In all the case it is compulsory to use the " alter table .." command claim the space.
===========
1) Take hotbackup for the instance
2) Execute the following commands as sysdba
SQL> delete from APPLSYS.FND_LOBS
SQL> alter table applsys.FND_LOBS modify lob (FILE_DATA) (shrink space);
3) Then Execute the following commands to confirm the space gained.
SQL> select round(sum(bytes)/1024/1024) Mb from dba_segments where segment_name='FND_LOBS';
SQL> select round(sum(bytes)/1024/1024) Mb from dba_segments where segment_name='SYS_LOB0000034032C00004$$';
NOTE: It should return "0" for both the commands.
Or
Update the LOB column value with NULL and then execute the following command.
SQL> alter table applsys.FND_LOBS modify lob (FILE_DATA) (shrink space);
OR
Use the DBMS_LOB.ERASE package and erase the LOBs. Then execute the following command ..
SQL> alter table applsys.FND_LOBS modify lob (FILE_DATA) (shrink space);
In all the case it is compulsory to use the " alter table .." command claim the space.
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