V$DATAFILE

This view contains datafile information from the control file.

See Also:

"V$DATAFILE_HEADER", which displays information from datafile headers

Column	Datatype	Description
`FILE#`	`NUMBER`	File identification number
`CREATION_CHANGE#`	`NUMBER`	Change number at which the datafile was created
`CREATION_TIME`	`DATE`	Timestamp of the datafile creation
`TS#`	`NUMBER`	Tablespace number
`RFILE#`	`NUMBER`	Tablespace relative datafile number
`STATUS`	`VARCHAR2(7)`	Type of file (system or user) and its status. Values: `OFFLINE`, `ONLINE`, `SYSTEM`, `RECOVER`, `SYSOFF` (an offline file from the `SYSTEM` tablespace)
`ENABLED`	`VARCHAR2(10)`	Describes how accessible the file is from SQL: `DISABLED` - No SQL access allowed `READ ONLY` - No SQL updates allowed `READ WRITE` - Full access allowed `UNKNOWN` - should not occur unless the control file is corrupted
`CHECKPOINT_CHANGE#`	`NUMBER`	SCN at last checkpoint
`CHECKPOINT_TIME`	`DATE`	Timestamp of the checkpoint#
`UNRECOVERABLE_CHANGE#`	`NUMBER`	Last unrecoverable change number made to this datafile. If the database is in `ARCHIVELOG` mode, then this column is updated when an unrecoverable operation completes. If the database is not in `ARCHIVELOG` mode, this column does not get updated.
`UNRECOVERABLE_TIME`	`DATE`	Timestamp of the last unrecoverable change. This column is updated only if the database is in `ARCHIVELOG` mode.
`LAST_CHANGE#`	`NUMBER`	Last change number made to this datafile (null if the datafile is being changed)
`LAST_TIME`	`DATE`	Timestamp of the last change
`OFFLINE_CHANGE#`	`NUMBER`	Offline change number of the last offline range. This column is updated only when the datafile is brought online.
`ONLINE_CHANGE#`	`NUMBER`	Online change number of the last offline range
`ONLINE_TIME`	`DATE`	Online timestamp of the last offline range
`BYTES`	`NUMBER`	Current datafile size (in bytes); `0` if inaccessible
`BLOCKS`	`NUMBER`	Current datafile size (in blocks); 0 if inaccessible
`CREATE_BYTES`	`NUMBER`	Size when created (in bytes)
`BLOCK_SIZE`	`NUMBER`	Block size of the datafile
`NAME`	`VARCHAR2(513)`	Name of the datafile
`PLUGGED_IN`	`NUMBER`	Describes whether the tablespace is plugged in. The value is `1` if the tablespace is plugged in and has not been made read/write, `0` if not.
`BLOCK1_OFFSET`	`NUMBER`	Offset from the beginning of the file to where the Oracle generic information begins. The exact length of the file can be computed as follows:`BYTES + BLOCK1_OFFSET`.
`AUX_NAME`	`VARCHAR2(513)`	Auxiliary name that has been set for this file via `CONFIGURE AUXNAME`
`FIRST_NONLOGGED_SCN`	`NUMBER`	First nonlogged SCN
`FIRST_NONLOGGED_TIME`	`DATE`	First nonlogged time

V$TEMPFILE

This view displays tempfile information.

Column	Datatype	Description
`FILE#`	`NUMBER`	Absolute file number
`CREATION_CHANGE#`	`NUMBER`	Creation System Change Number (SCN)
`CREATION_TIME`	`DATE`	Creation time
`TS#`	`NUMBER`	Tablespace number
`RFILE#`	`NUMBER`	Relative file number in the tablespace
`STATUS`	`VARCHAR2(7)`	Status of the file (`OFFLINE`\|`ONLINE`)
`ENABLED`	`VARCHAR2(10)`	Enabled for read and/or write
`BYTES`	`NUMBER`	Size of the file in bytes (from the file header)
`BLOCKS`	`NUMBER`	Size of the file in blocks (from the file header)
`CREATE_BYTES`	`NUMBER`	Creation size of the file (in bytes)
`BLOCK_SIZE`	`NUMBER`	Block size for the file
`NAME`	`VARCHAR2(513)`	Name of the file

从上面的文档能够看出。在v$tempfile和v$datafile中file#均代表绝对文件好，而rfile#代表相对文件号，以下来验证一下：

SQL> l

  1* select file#,name from v$tempfile

SQL> /

     FILE# NAME

---------- ------------------------------------------------------------

	 1 /home/app/oraten/oradata/oraten/temp01.dbf

SQL> select file#,name from v$datafile;

     FILE# NAME

---------- ------------------------------------------------------------

	 1 /home/app/oraten/oradata/oraten/system01.dbf

	 2 /home/app/oraten/oradata/oraten/undotbs01.dbf

	 3 /home/app/oraten/oradata/oraten/sysaux01.dbf

	 4 /home/app/oraten/oradata/oraten/users01.dbf

	 5 /home/app/oraten/oradata/oraten/test01.dbf

在v$datafile和v$tempfile中都存在绝对文件号为1的文件。这显然是不正确的。

我们知道在文件无法訪问时，oracle会报错并在错误信息中显示有关文件的信息，以下我们来模拟暂时文件的故障

[oraten@yue oraten]$ chmod 000 temp01.dbf

[oraten@yue oraten]$ ll

总用量 932180

-rw-r----- 1 oraten dba   7061504 11月  7 13:59 control01.ctl

-rw-r----- 1 oraten dba   7061504 11月  7 13:59 control02.ctl

-rw-r----- 1 oraten dba   7061504 11月  7 13:59 control03.ctl

-rw-r----- 1 oraten dba  52429312 11月  7 13:44 redo01.log

-rw-r----- 1 oraten dba  52429312 11月  7 13:54 redo02.log

-rw-r----- 1 oraten dba  52429312 11月  7 13:44 redo03.log

-rw-r----- 1 oraten dba 272637952 11月  7 13:49 sysaux01.dbf

-rw-r----- 1 oraten dba 461381632 11月  7 13:49 system01.dbf

---------- 1 oraten dba  20979712 11月  7 13:39 temp01.dbf

-rw-r----- 1 oraten dba  10493952 11月  7 13:44 test01.dbf

-rw-r----- 1 oraten dba  26222592 11月  7 13:49 undotbs01.dbf

-rw-r----- 1 oraten dba   5251072 11月  7 13:44 users01.dbf

强制启动数据库

SQL> startup force

ORACLE instance started.

Total System Global Area  134217728 bytes

Fixed Size		    2094544 bytes

Variable Size		   88082992 bytes

Database Buffers	   37748736 bytes

Redo Buffers		    6291456 bytes

Database mounted.

Database opened.

SQL>

创建暂时表。并插入数据

SQL> insert into t1 select * from user_tables;

insert into t1 select * from user_tables

            *

ERROR at line 1:

ORA-01157: cannot identify/lock data file 101 - see DBWR trace file

ORA-01110: data file 101: '/home/app/oraten/oradata/oraten/temp01.dbf'

呵呵，暂时文件无法訪问，在这里显示的文件号为101,为什么那？

我们将參数 db_files改动为200,继续实验

SQL> show parameter db_files

NAME				     TYPE	 VALUE

------------------------------------ ----------- ------------------------------

db_files			     integer	 100

SQL> alter system set db_files=200 scope=spfile;

System altered.

SQL> startup force

ORACLE instance started.

Total System Global Area  134217728 bytes

Fixed Size		    2094544 bytes

Variable Size		   88082992 bytes

Database Buffers	   37748736 bytes

Redo Buffers		    6291456 bytes

Database mounted.

Database opened.

SQL> insert into t1 select * from user_tables;

insert into t1 select * from user_tables

            *

ERROR at line 1:

ORA-01157: cannot identify/lock data file 201 - see DBWR trace file

ORA-01110: data file 201: '/home/app/oraten/oradata/oraten/temp01.dbf'

原来,v$tempfile中的file#并非绝对文件号。暂时文件的绝对文件号是file#+db_files參数。

打完手工！

！

巴特西

左右v$datafile和v$tempfile中间file#

V$DATAFILE

V$TEMPFILE

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