SQL*Plus: Release 10.2.0.1.0 - Production on Thu Nov 19 19:48:24 2009

Copyright (c) 1982, 2005, Oracle.  All rights reserved.

SQL> conn sys@live as sysdba
Enter password:
Connected.
SQL> SELECT SUM(value) "Redo Buffer Waits" FROM v$sysstat WHERE name = 'redo log space requests';

Redo Buffer Waits
-----------------
            23555

SQL>
SQL> SELECT SUM(value) "Redo Buffer Waits" FROM v$sysstat WHERE name = 'redo log space wait time';

Redo Buffer Waits
-----------------
          1155196

SQL>  SELECT name,SUM(value) "Redo Buffer Waits" FROM v$sysstat WHERE name  like '%redo log%'
  2   group by name
  3  /

NAME                                                             Redo Buffer Waits
----------------------------------------------------------------      -----------------------------
redo log space requests                                                      23557
redo log space wait time                                                   1155201
redo log switch interrupts                                                       0

SQL>


SQL> select  name, value  
  2  from    v$parameter
  3  where   name in ('cpu_count','log_parallelism','log_buffer')
  4  /

NAME                                                                             VALUE
-------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------
cpu_count                                                                        128
log_buffer                                                                       1253376

SQL> show sga

Total System Global Area 1.7952E+10 bytes
Fixed Size                  2170576 bytes
Variable Size            8552915248 bytes
Database Buffers         9395240960 bytes
Redo Buffers                1294336 bytes


SQL> select
  2    min(b.first_time - a.first_time) * 1440 * 60  seconds
  3  from
  4    sys.v_$instance  i,
  5    sys.v_$log_history  a,
  6    ( select
  7        sequence#,
  8        first_time
  9      from
 10        sys.v_$log
 11      where
 12        status = 'CURRENT'
 13      union all
 14      select
 15        sequence#,
 16        first_time
 17      from
 18        sys.v_$log_history
 19    )  b
 20  where
 21    i.startup_time < a.first_time and
 22    a.first_time < b.first_time and
 23    a.sequence# + 1 = b.sequence#
 24  /

   SECONDS
----------
         2

Alter system switch logfile;
alter system checkpoint;