Warning: log write elapsed time 1288ms, size 78KB

This warning message will be generated only if the log write time is more than 500 ms. this is a storage performance issue, either the storage has to get faster, or the application has to commit less. So check the performance of storage and analyze the commit frequency of application.

erpdcdb02$ cat erpdcdb2_lgwr_5046526.trc
Trace file /u01/app/oracle/diag/rdbms/erpdcdb/erpdcdb2/trace/erpdcdb2_lgwr_5046526.trc
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, Real Application Clusters, Automatic Storage Management, Oracle Label Security,
OLAP, Data Mining, Oracle Database Vault and Real Application Testing option
ORACLE_HOME = /u01/app/oracle/product/11.2.0/db_1
System name:    AIX
Node name:      erpdcdb02
Release:        1
Version:        7
Machine:        00F8FB754C00
Instance name: erpdcdb2
Redo thread mounted by this instance: 2
Oracle process number: 23
Unix process pid: 5046526, image: oracle@erpdcdb02 (LGWR)


*** 2016-10-27 13:47:38.631
*** SESSION ID:(10811.1) 2016-10-27 13:47:38.631
*** CLIENT ID:() 2016-10-27 13:47:38.631
*** SERVICE NAME:(SYS$BACKGROUND) 2016-10-27 13:47:38.631
*** MODULE NAME:() 2016-10-27 13:47:38.631
*** ACTION NAME:() 2016-10-27 13:47:38.631

Warning: log write elapsed time 1288ms, size 78KB
kcrfw_update_adaptive_sync_mode: post->poll long#=20 sync#=49 sync=299 poll=10019 rw=416 ack=13 min_sleep=10019

*** 2016-10-28 06:50:44.380
Log file sync switching to polling
Current scheduling delay is 1 usec
Current approximate redo synch write rate is 16 per sec
kcrfw_update_adaptive_sync_mode: poll->post current_sched_delay=187 switch_sched_delay=1 current_sync_count_delta=0 switch_sync_count_delta=49

*** 2016-10-28 07:12:28.017
Log file sync switching to post/wait
Current approximate redo synch write rate is 0 per sec
kcrfw_update_adaptive_sync_mode: post->poll long#=6 sync#=16 sync=172 poll=10019 rw=779 ack=0 min_sleep=10019

*** 2016-10-29 01:39:22.838
Log file sync switching to polling
Current scheduling delay is 250 usec
Current approximate redo synch write rate is 5 per sec
kcrfw_update_adaptive_sync_mode: poll->post current_sched_delay=0 switch_sched_delay=250 current_sync_count_delta=0 switch_sync_count_delta=16

*** 2016-10-29 01:52:14.212
Log file sync switching to post/wait
Current approximate redo synch write rate is 0 per sec