Oracle数据文件收缩
随着数据库的使用，数据文件越来越大，有没有办法将标记为free的block挤掉
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DBA_DATA_FILES
DBA_DATA_FILES describes database files.
Column Datatype NULL Description
FILE_NAME VARCHAR2(513) Name of the database file
FILE_ID NUMBER NOT NULL File identifier number of the database file
TABLESPACE_NAME VARCHAR2(30) NOT NULL Name of the tablespace to which the file belongs
BYTES NUMBER Size of the file in bytes
BLOCKS NUMBER NOT NULL Size of the file in Oracle blocks
STATUS VARCHAR2(9) File status: AVAILABLE or INVALID (INVALID means that the file number is not in use, for example, a file in a tablespace that was dropped)
RELATIVE_FNO NUMBER Relative file number
AUTOEXTENSIBLE VARCHAR2(3) Autoextensible indicator
MAXBYTES NUMBER Maximum file size in bytes
MAXBLOCKS NUMBER Maximum file size in blocks
INCREMENT_BY NUMBER Number of Oracle blocks used as autoextension increment
USER_BYTES NUMBER The size of the file available for user data. The actual size of the file minus the USER_BYTES value is used to store file related metadata.
USER_BLOCKS NUMBER Number of blocks which can be used by the data
ONLINE_STATUS VARCHAR2(7) Online status of the file:
SYSOFF
SYSTEM
OFFLINE
ONLINE
RECOVER
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DBA_FREE_SPACE
DBA_FREE_SPACE describes the free extents in all tablespaces in the database.
Note that if a datafile (or entire tablespace) is offline in a locally managed tablespace, you will not see any extent information. If an object has extents in an online file of the tablespace, you will see extent information about the offline datafile. However, if the object is entirely in the offline file, a query of this view will not return any records.
Related View
USER_FREE_SPACE describes the free extents in the tablespaces accessible to the current user.
Column Datatype NULL Description
TABLESPACE_NAME VARCHAR2(30) Name of the tablespace containing the extent
FILE_ID NUMBER File identifier number of the file containing the extent
BLOCK_ID NUMBER Starting block number of the extent
BYTES NUMBER Size of the extent (in bytes) --free bytes
BLOCKS NUMBER Size of the extent (in Oracle blocks) --free block
RELATIVE_FNO NUMBER Relative file number of the file containing the extent
DBA_EXTENTS
DBA_EXTENTS describes the extents comprising the segments in all tablespaces in the database.
Note that if a datafile (or entire tablespace) is offline in a locally managed tablespace, you will not see any extent information. If an object has extents in an online file of the tablespace, you will see extent information about the offline datafile. However, if the object is entirely in the offline file, a query of this view will not return any records.
Related View
USER_EXTENTS describes the extents comprising the segments owned by the current user's objects. This view does not display the OWNER, FILE_ID, BLOCK_ID, orRELATIVE_FNO columns.
Column Datatype NULL Description
OWNER VARCHAR2(30) Owner of the segment associated with the extent
SEGMENT_NAME VARCHAR2(81) Name of the segment associated with the extent
PARTITION_NAME VARCHAR2(30) Object Partition Name (Set to NULL for non-partitioned objects)
SEGMENT_TYPE VARCHAR2(18) Type of the segment: INDEX PARTITION, TABLE PARTITION
TABLESPACE_NAME VARCHAR2(30) Name of the tablespace containing the extent
EXTENT_ID NUMBER Extent number in the segment
FILE_ID NUMBER File identifier number of the file containing the extent
BLOCK_ID NUMBER Starting block number of the extent
BYTES NUMBER Size of the extent in bytes
BLOCKS NUMBER Size of the extent in Oracle blocks
RELATIVE_FNO NUMBER Relative file number of the first extent block
[sql]
SELECT 'alter database datafile '
||chr(39)
||file_name
||chr(39)
|| ' resize '
|| ceil(hwmsize*1.2)
||'M;'
FROM
(SELECT a.file_id,
a.file_name,
a.filesize,
b.freesize,
(a.filesize-b.freesize) usedsize,
c.hwmsize,
c.hwmsize - (a.filesize-b.freesize) unsedsize_belowhwm,
a.filesize - c.hwmsize canshrinksize
FROM ( select file_id,file_name,ROUND(bytes/1024/1024) filesize
FROM dba_data_files ) a,
( select file_id,ROUND(SUM(dfs.bytes)/1024/1024) freesize
FROM dba_free_space dfs group BY file_id ) b,
( select file_id,ROUND(MAX(block_id)*8/1024) HWMsize
FROM dba_extents group BY file_id) c where a.file_id = b.file_id and a.file_id = c.file_id order BY unsedsize_belowhwm DESC
)
[sql]
alter database datafile 'F:\ORACLE\ORADATA\PURPLE\USERS_NEW' resize 5755M;
alter database datafile 'F:\ORACLE\ORADATA\PURPLE\SYSTEM01.DBF' resize 4574M;
alter database datafile 'F:\ORACLE\ORADATA\PURPLE\INDEX_NEW' resize 825M;
alter database datafile 'F:\ORACLE\ORADATA\PURPLE\USERS01.DBF' resize 17980M;
alter database datafile 'F:\ORACLE\ORADATA\PURPLE\SYSAUX01.DBF' resize 670M;
alter database datafile 'F:\ORACLE\ORADATA\PURPLE\EXAMPLE01.DBF' resize 90M;
alter database datafile 'F:\ORACLE\ORADATA\PURPLE\UNDOTBS01.DBF' resize 72M;
总共释放出7G的空间出来。
