Log switch query

Hi,
What can force a log switch other than redo log filling or an alter system switch logfile?. reason I asked is I'm looking at a list of achived logs and only every other one seems to be the size of a redo log. the alert log dosn`t show any alter system commands. what is going on ?

Cheers, Mike.

archive dir sample -
-rw-r----- 1 oracle dba 5243392 Oct 5 13:38 PANL1_41717.dbf
-rw-r----- 1 oracle dba 2008064 Oct 5 13:40 PANL1_41718.dbf
-rw-r----- 1 oracle dba 5243392 Oct 5 13:43 PANL1_41719.dbf
-rw-r----- 1 oracle dba 1871872 Oct 5 13:45 PANL1_41720.dbf
-rw-r----- 1 oracle dba 5243392 Oct 5 13:49 PANL1_41721.dbf
-rw-r----- 1 oracle dba 1413120 Oct 5 13:50 PANL1_41722.dbf

alert log sample -

Completed database checkpoint by background Thu Oct 5 13:35:03 2000
ARCH: Archival stopped
Thu Oct 5 13:35:03 2000
Beginning database checkpoint by background Thu Oct 5 13:35:03 2000
Thread 1 advanced to log sequence 41717
  Current log# 3 seq# 41717 mem#
0: /gbmdclp1/oradata4/PANL/redo/PANLlog_3_1.dbf   Current log# 3 seq# 41717 mem#
1: /gbmdclp1/oradata5/PANL/redo/PANLlog_3_2.dbf   Current log# 3 seq# 41717 mem#
2: /gbmdclp1/oradata6/PANL/redo/PANLlog_3_3.dbf Thu Oct 5 13:35:05 2000
ARCH: Archival started
Thu Oct 5 13:35:07 2000
Completed database checkpoint by background Thu Oct 5 13:38:25 2000
Beginning database checkpoint by background Thu Oct 5 13:38:25 2000
Thread 1 advanced to log sequence 41718
  Current log# 2 seq# 41718 mem#
0: /gbmdclp1/oradata4/PANL/redo/PANLlog_2_1.dbf   Current log# 2 seq# 41718 mem#
1: /gbmdclp1/oradata5/PANL/redo/PANLlog_2_2.dbf   Current log# 2 seq# 41718 mem#
2: /gbmdclp1/oradata6/PANL/redo/PANLlog_2_3.dbf Thu Oct 5 13:38:26 2000
Completed database checkpoint by background Thu Oct 5 13:40:02 2000
ARCH: Archival stopped
Thu Oct 5 13:40:03 2000
Beginning database checkpoint by background Thu Oct 5 13:40:03 2000
Thread 1 advanced to log sequence 41719
  Current log# 1 seq# 41719 mem#
0: /gbmdclp1/oradata4/PANL/redo/PANLlog_1_1.dbf   Current log# 1 seq# 41719 mem#
1: /gbmdclp1/oradata5/PANL/redo/PANLlog_1_2.dbf   Current log# 1 seq# 41719 mem#
2: /gbmdclp1/oradata6/PANL/redo/PANLlog_1_3.dbf Thu Oct 5 13:40:04 2000
ARCH: Archival started
Thu Oct 5 13:40:06 2000
Completed database checkpoint by background Thu Oct 5 13:43:21 2000
Beginning database checkpoint by background Thu Oct 5 13:43:21 2000
Thread 1 advanced to log sequence 41720
  Current log# 3 seq# 41720 mem#
0: /gbmdclp1/oradata4/PANL/redo/PANLlog_3_1.dbf   Current log# 3 seq# 41720 mem#
1: /gbmdclp1/oradata5/PANL/redo/PANLlog_3_2.dbf   Current log# 3 seq# 41720 mem#
2: /gbmdclp1/oradata6/PANL/redo/PANLlog_3_3.dbf Thu Oct 5 13:43:25 2000
Completed database checkpoint by background Thu Oct 5 13:45:02 2000
ARCH: Archival stopped
Thu Oct 5 13:45:03 2000
Beginning database checkpoint by background Thu Oct 5 13:45:03 2000
Thread 1 advanced to log sequence 41721
  Current log# 2 seq# 41721 mem#
0: /gbmdclp1/oradata4/PANL/redo/PANLlog_2_1.dbf   Current log# 2 seq# 41721 mem#
1: /gbmdclp1/oradata5/PANL/redo/PANLlog_2_2.dbf   Current log# 2 seq# 41721 mem#
2: /gbmdclp1/oradata6/PANL/redo/PANLlog_2_3.dbf Thu Oct 5 13:45:05 2000
ARCH: Archival started
Thu Oct 5 13:45:05 2000
Completed database checkpoint by background Thu Oct 5 13:49:10 2000
Beginning database checkpoint by background Thu Oct 5 13:49:10 2000
Thread 1 advanced to log sequence 41722
  Current log# 1 seq# 41722 mem#
0: /gbmdclp1/oradata4/PANL/redo/PANLlog_1_1.dbf   Current log# 1 seq# 41722 mem#
1: /gbmdclp1/oradata5/PANL/redo/PANLlog_1_2.dbf   Current log# 1 seq# 41722 mem#
2: /gbmdclp1/oradata6/PANL/redo/PANLlog_1_3.dbf Thu Oct 5 13:49:12 2000
Completed database checkpoint by background Thu Oct 5 13:50:02 2000
ARCH: Archival stopped
Thu Oct 5 13:50:03 2000
Beginning database checkpoint by background Thu Oct 5 13:50:03 2000
Thread 1 advanced to log sequence 41723
  Current log# 3 seq# 41723 mem#
0: /gbmdclp1/oradata4/PANL/redo/PANLlog_3_1.dbf   Current log# 3 seq# 41723 mem#
1: /gbmdclp1/oradata5/PANL/redo/PANLlog_3_2.dbf   Current log# 3 seq# 41723 mem#
2: /gbmdclp1/oradata6/PANL/redo/PANLlog_3_3.dbf Thu Oct 5 13:50:06 2000
ARCH: Archival started
Thu Oct 5 13:50:08 2000
Completed database checkpoint by background

Sent via Deja.com http://www.deja.com/
Before you buy. Received on Thu Oct 05 2000 - 08:55:13 CDT