Alert.log: New timestamp format in Oracle 12.2

Timestamp Format Change

There’s an interesting change in the alert.log since Oracle Database 12.2.0.1: The format of the timestamps has changed.

If you compare the timestamps in Oracle 12.1 vs Oracle 12.2 you’ll recognize the change immediately:

Oracle 12.1 Oracle 12.2
Wed Feb 08 15:39:29 2017
Database mounted in Exclusive Mode
Lost write protection disabled
Completed: ALTER DATABASE   MOUNT
Wed Feb 08 15:39:29 2017
ALTER DATABASE OPEN
Wed Feb 08 15:39:29 2017
Ping without log force is disabled.
Starting background process TMON

2017-05-29T14:09:17.064493+02:00
Database mounted in Exclusive Mode
Lost write protection disabled
Completed: ALTER DATABASE   MOUNT
2017-05-29T14:09:17.252853+02:00
ALTER DATABASE OPEN
2017-05-29T14:09:17.266894+02:00
Ping without log force is disabled:
  instance mounted in exclusive mode.
Endian type of dictionary set to little

Revert to the old format?

In some cases you may wish to revert to the old display format, for instance if you extract information from the alert.log and rely on the old timestamp format. In case you’d like to change it please use the init.ora/spfile parameter UNIFORM_LOG_TIMESTAMP_FORMAT. Default setting is TRUE. Once you switch it to FALSE the timestamp in the alert.log is in pre-Oracle-12.2 format dynamically.

ALTER SYSTEM SET uniform_log_timestamp_format=FALSE SCOPE=BOTH;
Completed: ALTER DATABASE OPEN
2017-05-29T14:29:42.174973+02:00
Shared IO Pool defaulting to 64MB. Trying to get it from Buffer Cache for process 20948.
===========================================================
Dumping current patch information
===========================================================
Patch Id: 25862693
Patch Description: DATABASE BUNDLE PATCH: 12.2.0.1.170516 (25862693)
Patch Apply Time: 2017-05-19T17:49:59+02:00
Bugs Fixed: 23026585,24336249,24385983,24923215,24929210,24942749,25036474,
25099758,25110233,25410877,25417050,25427662,25429959,25459958,25547901,
25569149,25600342,25600421,25606091,25655390,25662088,25662101,25728085,
25823754
===========================================================
Mon May 29 14:37:08 2017
ALTER SYSTEM SET uniform_log_timestamp_format=FALSE SCOPE=BOTH;
Mon May 29 14:37:25 2017
Thread 1 advanced to log sequence 16 (LGWR switch)
  Current log# 1 seq# 16 mem# 0: /u02/oradata/CDB2/redo01.log

Oracle Clusterware, ASM, Grid Infrastructure?

Luckily Anil Nair, our RAC PM, has been blogged about the influence of this new setting on the Clusterware and ASM logs:

Further Information

–Mike

PS: Thanks to Roderick for CC:ing me and for filing a doc bug 26145504 to get this added into the next revision of the Upgrade Guide as Behavior Change.

One thought on “Alert.log: New timestamp format in Oracle 12.2

Leave a Reply

Your email address will not be published. Required fields are marked *