Overview

This guide provides the essential configuration files for operating Tibero Single DB.

Method

3. Essential Tibero Configuration Files

3.1. Redo Log File

Records all changes to data and provides recovery methods in case of Media Failure.

Configured with at least two or more groups (Mirroring).

3.1.1. Checking Redo Log Files

SQL> select * from v$logfile;

    GROUP# STATUS  TYPE   MEMBER
--------------- ------------ ---------- ------------------------------
         0            ONLINE /tibero/tbdata/redo_1/log001.log 
         1            ONLINE /tibero/tbdata/redo_1/log011.log 
         2            ONLINE /tibero/tbdata/redo_1/log021.log 

⇒ Currently, there is 1 log file (1 member) in each of the 3 groups, all in Online status.



SQL> select group#, members, archived, status from v$log;

    GROUP#  MEMBERS  ARCHIVED  STATUS
----------------  --------------- ---------------- --------
            0          1      YES         INACTIVE
            1          1      YES         INACTIVE
            2          1      NO         CURRENT


⇒ It can be confirmed that log files are currently being written to Group 2. 
    When the CURRENT log file is full or a manual log switch is triggered, the next log file becomes CURRENT, and redo logs are recorded.

3.1.2. Adding Redo Log Files / Mirroring

SQL> select * from v$logfile;

    GROUP#  STATUS     TYPE   MEMBER
----------------- -------------- ----------- -----------------------------------
         0               ONLINE /tibero/tbdata/redo_1/log001.log
         1               ONLINE /tibero/tbdata/redo_1/log011.log
         2               ONLINE /tibero/tbdata/redo_1/log021.log

⇒ Check the current Redo Log File configuration.



SQL> alter database add logfile member '/tibero/tbdata/redo_2/log002.log' to group 0;
SQL> alter database add logfile member '/tibero/tbdata/redo_2/log012.log' to group 1;

⇒ Add log file members to each group to mirror the redo log files.
⇒ Since Group 2 is currently in CURRENT status, add members to Groups 0 and 1 which are in INACTIVE status first.



SQL> select * from v$logfile;

    GROUP#   STATUS    TYPE   MEMBER
---------------- ---------------- ----------- -----------------------------------
         0                ONLINE /tibero/tbdata/redo_1/log001.log
         0                ONLINE /tibero/tbdata/redo_2/log002.log
         1                ONLINE /tibero/tbdata/redo_1/log011.log
         1                ONLINE /tibero/tbdata/redo_2/log012.log
         2                ONLINE /tibero/tbdata/redo_1/log021.log

⇒ It can be seen that members were added to Groups 0 and 1.
⇒ Since Group 2 is in CURRENT status, member addition cannot be performed at this time.



SQL> alter system switch logfile; 
SQL> select group#, members, archived, status from v$log;

    GROUP#      MEMBERS   ARCHIVED  STATUS
----------------- ------------------ ----------------- -------------
            0                2        NO       CURRENT
            1                2        YES      INACTIVE
            2                1        YES      INACTIVE

⇒ Manually switch logs to make Group 2 INACTIVE.



SQL> alter database add logfile member '/tibero/tbdata/redo_2/log022.log' to group 2;
SQL> select * from v$logfile;

    GROUP#  STATUS  TYPE    MEMBER
----------------- ------------ ----------- -----------------------------------
         0               ONLINE /tibero/tbdata/redo_1/log001.log
         0               ONLINE /tibero/tbdata/redo_2/log002.log
         1               ONLINE /tibero/tbdata/redo_1/log011.log
         1               ONLINE /tibero/tbdata/redo_2/log012.log
         2               ONLINE /tibero/tbdata/redo_1/log021.log
         2               ONLINE /tibero/tbdata/redo_2/log022.log

⇒ Confirmed that a member was added to Group 2, so all groups now have 2 members.

Note

Since redo log files are often mistakenly deleted or nulled by confusing them with regular log files, careful management of redo log files is required.

3.2. Control File

An essential file for maintaining database integrity, recording the location of data files and the physical database's current status.

Required during database mount and open stages; if lost, the entire database becomes unusable and must be recovered.

3.2.1. Checking Control Files

SQL> select * from v$controlfile;

    STATUS NAME                            BLKSIZE   BLOCKS
--------------- --------------------------------------- ----------   ----------
           0 /tibero/tbdata/cont_1/c1.ctl     16384      4645
          0 /tibero/tbdata/cont_2/c2.ctl      16384      4645



⇒ Control files are created and maintained in duplicate to prepare for loss. 
   It is recommended to create them in different storage locations to increase stability.

3.2.2. Control File Backup

Since control files are very important for database operation, it is recommended to back them up regularly.

SQL> alter database backup controlfile to trace as '/tibero/tbdata/_BACKUP/control.sql';
Database altered.

⇒ Executing the above command backs up the control file as a text file containing the creation query at the path specified after ‘to trace as’. 
  This backup file can be used for recovery if the control file is damaged or deleted later.



$ ls -l /tibero/tbdata/_BACKUP
total 8
-rw-r--r-- 1 tibero dba 4124 Mar 27 05:35 control.sql

⇒ You can verify the backup file using the ls command in the specified OS path.

3.3. Datafile

The physical storage space where actual data is stored; multiple datafiles can exist within one tablespace (logical storage unit).

3.3.1. Checking Datafiles

SQL> select tablespace_name, file_name, bytes/1024/1024 from dba_data_files;

TABLESPACE_NAME  FILE_NAME                             BYTES/1024/1024
--------------------------  ------------------------------------------------- ---------------------
SYSTEM               /tibero/tbdata/data/system001.dtf               110
UNDO                 /tibero/tbdata/data/undo001.dtf                  200
USR                    /tibero/tbdata/data/usr001.dtf                    100
SYSSUB              /tibero/tbdata/data/syssub001.dtf                  20
TEST01                /tibero/tbdata/data/test01001.dtf                 100
TEST02                /tibero/tbdata/data/test02001.dtf                 100

6 rows selected.


⇒ This command shows the tablespace name, the file name belonging to the tablespace, and the file size. ‘BYTES/1024/1024’ converts the file size to megabytes.



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

     FILE#    NAME                                    STATUS
-------------- ----------------------------------------------- -------------------
          0 /tibero/tbdata/data/system001.dtf      ONLINE
          1 /tibero/tbdata/data/undo001.dtf        ONLINE
          2 /tibero/tbdata/data/usr001.dtf          ONLINE
          3 /tibero/tbdata/data/syssub001.dtf      ONLINE
          4 /tibero/tbdata/data/test01001.dtf      ONLINE
          5 /tibero/tbdata/data/test02001.dtf      ONLINE

6 rows selected.


⇒ This command also retrieves a list of datafiles existing in the database.

Note

The above redo log files, control files, and datafiles are essential files related to Tibero operation and must be regularly backed up and managed.