Dropping a Cache Group
Use the DROP CACHE GROUP
statement to drop a cache group and its
cache tables.
Oracle Database objects used to manage the caching of Oracle Database data are automatically dropped when you use the DROP CACHE GROUP
statement to drop a cache group.
If you issue a DROP CACHE GROUP
statement on a cache group that has an autorefresh operation in progress:
-
The autorefresh operation stops if the
LockWait
connection attribute setting is greater than 0. TheDROP CACHE GROUP
statement preempts the autorefresh operation. -
The autorefresh operation continues if the
LockWait
connection attribute setting is 0. TheDROP CACHE GROUP
statement is blocked until the autorefresh operation completes or the statement fails with a lock timeout error.
If you have created an AWT cache group, a replication scheme is created to enable committed changes on its cache tables to be asynchronously propagated to the cached Oracle tables. This replication scheme is automatically dropped when you drop the AWT cache group. Thus, perform the following before dropping an AWT cache group:
-
Use the
ttRepSubscriberWait
built-in procedure to make sure that all committed changes on its cache tables have been propagated to the cached Oracle Database tables before dropping the AWT cache group.% ttIsql "DSN=cache1;UID=cacheadmin;PwdWallet=/wallets/cacheadminwallet" Command> CALL ttRepSubscriberWait('_AWTREPSCHEME','TTREP','_ORACLE','sys1',-1);
-
The cache tables in an AWT cache group are replicated in an active standby pair. If the cache tables are the only tables that are being replicated, drop the active standby pair using a
DROP ACTIVE STANDBY PAIR
statement before dropping the AWT cache groups.Run the following statement as the TimesTen cache administration user on the
cacheactive
,cachestandby
androsubscriber
databases to drop the active standby pair replication scheme:Command> DROP ACTIVE STANDBY PAIR; Command> exit
Perform the following when dropping a cache group: