Restoring the TimesTen and Oracle Database Systems

Complete the following tasks to restore the TimesTen and Oracle database systems to their original state.

  1. Dropping Cache Groups.

  2. Stopping the Cache Agents for TimesTen Scaleout.

  3. Dropping the Oracle Database Users and Their Objects.

Dropping Cache Groups

Start the ttIsql utility and connect to the database1 DSN as the instance administrator. Use ttIsql to grant the DROP ANY TABLE privilege to the TimesTen cache administration user so that this user can drop the underlying cache tables when dropping the cache groups.

% ttIsql "DSN=database1"
Command> GRANT DROP ANY TABLE TO cacheadmin;
Command> exit

In order to drop the cache group, you should first pause the autorefresh operations to avoid any contention. Start the ttIsql utility and connect to the database1 DSN as the TimesTen cache administration user.

  1. Use an ALTER CACHE GROUP statement to set the cache group's autorefresh state to PAUSED.

  2. Use DROP CACHE GROUP statement to drop the readcache read-only cache group.

% ttIsql "DSN=database1;UID=cacheadmin;PwdWallet=/wallets/cacheadminwallet"
Command> ALTER CACHE GROUP readcache SET AUTOREFRESH STATE PAUSED;
Command> DROP CACHE GROUP readcache;

The readcache cache group and its cache table sales.readtab are dropped from the TimesTen database.

See Dropping a Cache Group in the Oracle TimesTen In-Memory Database Cache Guide.

Stopping the Cache Agents for TimesTen Scaleout

On the active management instance, use ttGridAdmin dbCacheStop command to stop the cache agent on all data instances within the database.

% ttGridAdmin dbCacheStop database1
Database database1 : Stopping cache agents. 

Database database1 element level status as of Mon Dec  7 14:52:51 PST 2020
 
Host  Instance  Elem Status CA Status Date/Time of Event  Message 
----- --------- ---- ------ --------- ------------------- ------- 
host3 instance1    1 opened stopped   2020-11-23 08:37:35         
host4 instance1    2 opened stopped   2020-11-23 08:37:35         
host5 instance1    3 opened stopped   2020-11-23 08:37:35         
host6 instance1    4 opened stopped   2020-11-23 08:37:35         
host7 instance1    5 opened stopped   2020-11-23 08:37:35         
host8 instance1    6 opened stopped   2020-11-23 08:37:35 

You can stop the cache agent for a specific data instance if you specify the -instance option.

% ttGridAdmin dbCacheStop database1 -instance host4.instance1
Database database1 : Stopping cache agents. 

% ttGridadmin dbStatus database1 -element
 
Database database1 element level status as of Mon Dec  7 14:52:51 PST 2020
 
Host  Instance  Elem Status CA Status Date/Time of Event  Message 
----- --------- ---- ------ --------- ------------------- ------- 
host3 instance1    1 opened started   2020-11-23 08:37:35         
host4 instance1    2 opened stopped   2020-11-23 08:37:35         
host5 instance1    3 opened started   2020-11-23 08:37:35         
host6 instance1    4 opened started   2020-11-23 08:37:35         
host7 instance1    5 opened started   2020-11-23 08:37:35         
host8 instance1    6 opened started   2020-11-23 08:37:35 

If there is only one cache agent running, do not stop the last cache agent immediately after you have dropped or altered a cache group with autorefresh. Instead, wait for at least two minutes to enable the cache agent to clean up Oracle database objects such as change log tables and triggers that were created and used to manage the cache group. This is not an issue when you have more than one cache agent running.

See Start a Cache Agent for TimesTen Scaleout.

Dropping the Oracle Database Users and Their Objects

Start SQL*Plus and connect to the Oracle database as the sys user. Use SQL*Plus to drop the Oracle cache administration user cacheadmin.

% sqlplus sys as sysdba
Enter password: password
SQL> DROP USER cacheadmin CASCADE;
User dropped.

Specifying CASCADE in a DROP USER statement drops all objects such as tables and triggers owned by the user before dropping the user itself.

Next use SQL*Plus to drop the TT_CACHE_ADMIN_ROLE role:

SQL> DROP ROLE TT_CACHE_ADMIN_ROLE;
Role dropped.

Then use SQL*Plus to drop the default tablespace cachetblsp used by the Oracle cache administration user including the contents of the tablespace and its data file:

SQL> DROP TABLESPACE cachetblsp INCLUDING CONTENTS AND DATAFILES;
Tablespace dropped.
SQL> exit