How to modify data file path in DM database

In real business , We sometimes encounter the situation that the disk is full , At this point, you need to transfer the data file to the newly attached disk , This is the path modification of the data file . The path modification of the data file includes ordinary table spaces 、 SYSTEM tablespace 、TEMP Table spaces and ROLL Rollback the data file of the tablespace , And redo log files , The following will be explained according to the situation .

Common tablespace data file path modification

The path of the data file can only be modified in the offline state of the ordinary table space , So before we modify the data file path of the ordinary table space , You need to query the tablespace information where the data file is located .

(1) Query tablespace and data file information

Use as follows SQL Statement to query tablespace and data file information ：

select a.file_name,a.file_id,a.tablespace_name,a.status,a.bytesfrom dba_data_files aorder by a.tablespace_name,a.file_id;
 The query results are as follows ：

(2) Modify data file path information

If we need to modify TBS Two data files of ordinary table space to TBS Under the folder （ To be guaranteed TBS Folder exists ）, At this time, you can use the following SQL sentence , The operation steps are as follows ：

① Take the tablespace where the data file is located offline ：

alter tablespace TBS offline;

② Modify data file path ：

alter tablespace TBS rename datafile'/dm/data/DAMENG/TBS01.dbf'to'/dm/data/DAMENG/TBS/TBS01.dbf';alter tablespace TBS rename datafile'/dm/data/DAMENG/TBS02.dbf'to'/dm/data/DAMENG/TBS/TBS02.dbf';

③ Online the tablespace where the data file is located ：

alter tablespace TBS online;

Complete the above steps , Reexamine dba_data_files, At this time, the data file path has been modified to a new path . As shown in the figure below ：

Be careful , When transferring data files , Because you want to take the tablespace offline for a short time , It will affect the operation of related businesses , Therefore, it is necessary to inform customers in advance of short-term business interruption . in addition , When transferring data files , Note that the new data file path exists , And belongs to dmdba User group .

in addition ,DM The client management tool can also modify the data file path of the table space , This principle is similar to the above SQL Agreement , After the interface operation, the bottom layer calls three of the above operation steps .

Redo log file path modification

Because redo logs are online , Cannot take redo logs offline , Therefore, the path of the redo log file can only be modified in mount Modify in status .

(1) Query redo log file information

Before modifying the data file , First understand the redo log file information , Use as follows SQL Statement query ：

select t.group_id,t.file_id, t.path, t.rlog_size from v$rlogfile t;

The query results are as follows ：

(2) Modify the path information of redo log file

Before modifying the redo log file path , You need to set the database to mount state , Then modify the path information of redo log file . For example, we modify the redo log to /dm/data/DAMENG/REDO route , The operation steps are as follows ：

① Switch the database to mount state ：

alter database mount;

② Modify the path of redo log file ：​​​​​​​

alter database rename logfile'/dm/data/DAMENG/DAMENG01.log'to'/dm/data/DAMENG/REDO/DAMENG01.log';alter database rename logfile'/dm/data/DAMENG/DAMENG02.log'to'/dm/data/DAMENG/REDO/DAMENG02.log';

③ Switch the database to open state ：

alter database open;

Complete the above steps , Reexamine V$RLOGFILE, At this time, the path of redo log file has been changed to a new path . As shown in the figure below ：

Be careful , When transferring redo log files , Because the database should be set to mount state , At this time, the database cannot provide normal services , It will affect the operation of the business . When transferring redo log files, you should pay attention to the existence of new paths , And belongs to dmdba User group .

in addition ,DM The client management tool can also modify the redo log file path , This principle is similar to the above SQL The sentences are consistent .DM The management tool needs to set the database to the configuration state first （MOUNT）, Then modify the path of redo log file .

SYSTEM tablespace 、ROLL Table space data file

Path modification

because SYSTEM SYSTEM tablespace 、ROLL Rollback tablespace does not allow offline , System tablespaces and ROLL The path modification of the tablespace data file can only be completed by modifying the path of the corresponding data file in the control file .

DM The control file is a binary file , Cannot edit directly , Need to use dmctlcvt After the tool is converted to a text file, edit . Be careful , Modify the system tablespace 、UNDO Tablespaces require manual copying of files , To maintain data consistency , Need to close database , Then copy the data file . The specific operation steps are as follows ：

① The control file dm.ctl Convert to text file

perform dmctlcvt help You can view help for using this command . As shown in the figure below ：

Execute the following command , The control file dm.ctl Convert to text file dmctl.txt：​​​​​​​

[[email protected]~]$ dmctlcvt type=1 src=/dm/data/DAMENG/dm.ctldest=/dm/data/DAMENG/dmctl.txt

② Modify the data file path in the text file

perform vi dmctl.txt Edit the generated text file , Modify the system tablespace 、ROLL The tablespace data file path is a new path , If it is modified to /dm/data/DAMENG/NEW Folder .

③ Convert the modified text file into the target control file

Execute the following command , The modified text file dmctl.txt Convert to new control file dmnew.ctl：​​​​​​​

[[email protected]~]$ dmctlcvt type=2 src=/dm/data/DAMENG/dmctl.txtdest=/dm/data/DAMENG/dmnew.ctl

④ Close the database , Copy the data file to the new path

Close the database , Copy SYSTEM.DBF and ROLL.DBF To the new data file path /dm/data/DAMENG/NEW, After copying , Rename the new control file to overwrite the original control file . Start the database after completion , Reexamine dba_data_files View , You can see the system table space and ROLL The tablespace file path has been modified . Here's the picture ：

actually , This method can also be used to modify the path of data files and redo log files in ordinary table spaces , But this method requires closing the database , And transform the control documents , The operation did not SQL Sentence or DM The management tool interface is direct and convenient , If only for ordinary table spaces and online redo logs , This method is not recommended .

TEMP Table space data file path modification

TEMP The path of the table space is dm.ini Configured in , The parameter name is TEMP_PATH. Only need to modify when modifying dm.ini in TEMP_PATH Parameter values , because TEMP_PATH by READONLY type , So you can only modify it manually dm.ini file , And restart the database to take effect .TEMP The modification of table space path does not need to be copied TEMP.DBF, When the database starts, the file will be regenerated under the configuration path .

Here's the picture , Use vi dm.ini modify dm.ini In file TEMP_PATH by /dm/data/DAMENG/NEW.

After the modification is completed , Restart the database , Inquire about dba_data_files View , You can see TEMP The data file path of the tablespace has been modified . Here's the picture ：