Oracle Doc Error

From: Daniel Roy <danielroy10junk_at_hotmail.com>
Date: 21 Jan 2004 19:57:02 -0800
Message-ID: <3722db.0401211957.eb6c17d@posting.google.com>

Guys,
  I was going through the chapter 7 of the Admin guide 9.2 on tahiti.oracle.com, about the redo logs. On that page, Oracle states that "If you need to drop the current group, first force a log switch to occur.". This looked fishy to me, so I decided to test it:

SQL> select * from v$log;

   GROUP# THREAD# SEQUENCE# BYTES MEMBERS ARC STATUS ---------- ---------- ---------- ---------- ---------- ---

---

FIRST_CHANGE# FIRST_TIM
------------- ---------

         1          1        181  104857600          1 NO  INACTIVE
      7112405 19-JAN-04

         2          1        182  104857600          1 NO  CURRENT
      7135173 21-JAN-04

         3          1        180  104857600          1 NO  INACTIVE
      7112401 19-JAN-04

SQL> alter system switch logfile;

System altered.

SQL> select * from v$log;

    GROUP# THREAD# SEQUENCE# BYTES MEMBERS ARC STATUS ---------- ---------- ---------- ---------- ---------- ---

---

FIRST_CHANGE# FIRST_TIM
------------- ---------

         1          1        181  104857600          1 NO  INACTIVE
      7112405 19-JAN-04

         2          1        182  104857600          1 NO  ACTIVE
      7135173 21-JAN-04

         3          1        183  104857600          1 NO  CURRENT
      7135646 21-JAN-04

SQL> alter database drop logfile group 2; alter database drop logfile group 2
*
ERROR at line 1:
ORA-01624: log 2 needed for crash recovery of thread 1 ORA-00312: online log 2 thread 1:
'C:\ORA9201\ORADATA\OEMREP\REDO02.LOG' SQL> alter system checkpoint;

System altered.

SQL> alter database drop logfile group 2;

Database altered.

As you can see, it seems to me that before being able to drop a log group, a log switch must of course have occurred. But a checkpoint up to at least the end of the log group must also have occurred! Is my counter-example correct, or I'm missing something?

Daniel Received on Wed Jan 21 2004 - 21:57:02 CST