Document TypeㅣTechnical Information
FieldㅣInstallation
Applicable Product Versionㅣ 7FS027FS02PS
Document Numberㅣ TINT001
Overview
When switching to Snapshot Standby in TSC (Tibero Standby Cluster), the Standby DB switches to a mode where it maintains redo synchronization with the Primary DB while allowing independent execution of DDL/DML operations.
This feature is mainly used for testing (DB cloning purposes) or DR environment verification.
Changes after switching to Snapshot are stored in the Online Logfile and Flashback Logfile.
Logs received from the Primary DB are stored in the Standby Redo Log Group.
During TSC recovery, it is only possible to switch to the point of Snapshot Standby change.
Restrictions
1. The same restrictions as Flashback Database apply.
2. Flashback Log File multiplexing feature is not supported.
3. Failover is not possible in Snapshot Standby state.
Key Parameters
FLASHBACK_LOG_BUFFER=100M USE_STANDBY_REDO_LOG=Y
Method
1. TSC Configuration
TSC configuration between Primary and Standby must be completed.
2. Standby DB: Parameter Settings ($TB_SID.tip)
-- Primary DB LOG_REPLICATION_MODE=PERFORMANCE LOG_REPLICATION_DEST_1="192.168.179.66:8862 LGWR ASYNC" -- Standby DB _STANDBY_CONN_PORT=8862 _STANDBY_NETWORK_TIMEOUT=60 FLASHBACK_LOG_BUFFER=100M USE_STANDBY_REDO_LOG=Y
3. Standby: Create Redo Log Group
Check the Redo Log Group and size, then add Standby Redo Log Groups with the same group numbers and count as the Redo Log Files.
SQL> alter database add standby logfile thread 0 group 0 '/home/tibero7/database/tibero1/srl01.redo' size 50M; SQL> alter database add standby logfile thread 0 group 1 '/home/tibero7/database/tibero1/srl02.redo' size 50M; SQL> alter database add standby logfile thread 0 group 2 '/home/tibero7/database/tibero1/srl03.redo' size 50M;
4. Standby DB: Enable Redo Log Thread
SQL> alter database enable public standby redo thread 0;
5. Standby DB: Perform MR (Media Recovery)
SQL> alter database recover automatic for standby;
6. Standby DB: Configure Flashback Log and Enable Thread (Mount mode)
SQL> alter database add flashback logfile thread 0 group 0 '/home/viera/tibero7/database/tibero1/fblog001.fb' size 50M; SQL> alter database add flashback logfile thread 0 group 1 '/home/viera/tibero7/database/tibero1/fblog002.fb' size 50M; SQL> alter database add flashback logfile thread 0 group 2 '/home/viera/tibero7/database/tibero1/fblog003.fb' size 50M; SQL> alter database enable public flashback thread 0;
7. Standby DB: Switch to Snapshot Standby
SQL> alter database convert to snapshot standby;
8. Standby DB: Restart DB (Resetlogs mode)
$ tbdown immediate $ tbboot -t resetlogs
9. Standby DB: Confirm Switch
SQL> select DATABASE_ROLE from v$database; DATABASE_ROLE ----------------- SNAPSHOT STANDBY