What will happen if I delete ACTIVE logfile member

Question

hi gurus
JUST FOR TESTING.
Consider the situation as follows
I create a table,insert some rows into the table,then do a log switch. And then I remove the logfile which still in the "ACTIVE" states with operating system command.
Finally I shutdown and restart the database, the database complains that the logfile group does not
exist,so I drop the logfile group and open the database. I run a query against the table I created before,data still exists.
The result of the test make me fell strange.
Accornding to my knowledge, logfile in the 'ACTIVE' state means that the data protected by the logfile have not been written to the datafile.So I expect the table will not exists after I drop the logfile and then restart the database.
Why the data are still there?
Thanks a lot.

Answer 1

hi Hashmi
Testcase:
SQL> select group#,status from v$log;
GROUP# STATUS
+1 INACTIVE+
+2 INACTIVE+
+3 CURRENT+
SQL> select member from v$logfile where group#=3;
MEMBER
+/oracle/app/oracle/oradata/TESTDB/onlinelog/o1_mf_3_5tg3h0nz_.log+
+/oracle/app/oracle/flash_recovery_area/TESTDB/onlinelog/o1_mf_3_5tg3h29l_.log+
SQL> drop table yef;
Table dropped.
SQL> create table yef as select * from system.maoxl;
Table created.
SQL> select group#,status from v$log;
GROUP# STATUS
+1 INACTIVE+
+2 INACTIVE+
+3 CURRENT+
SQL>
SQL> alter system switch logfile;
System altered.
SQL> select group#,status from v$log;
GROUP# STATUS
+1 CURRENT+
+2 INACTIVE+
+3 ACTIVE+
SQL> host rm /oracle/app/oracle/oradata/TESTDB/onlinelog/o1_mf_3_5tg3h0nz_.log
SQL> host rm /oracle/app/oracle/flash_recovery_area/TESTDB/onlinelog/o1_mf_3_5tg3h29l_.log
SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup;
ORACLE instance started.
Total System Global Area 2097152000 bytes
Fixed Size                  2401464 bytes
Variable Size             480947016 bytes
Database Buffers         1593835520 bytes
Redo Buffers               19968000 bytes
Database mounted.
ORA-00313: open failed for members of log group 3 of thread 1
ORA-00312: online log 3 thread 1: '/oracle/app/oracle/oradata/TESTDB/onlinelog/o1_mf_3_5tg3h0nz_.log'
ORA-00312: online log 3 thread 1: '/oracle/app/oracle/flash_recovery_area/TESTDB/onlinelog/o1_mf_3_5tg3h29l_.log'
SQL> select group#,status from v$log;
GROUP# STATUS
+1 CURRENT+
+3 INACTIVE+
+2 INACTIVE+
SQL> alter database drop logfile group 3;
Database altered.
SQL> alter database open;
Database altered.
SQL> select * from yef;
ID
+1+
+4+
+4+
SQL>