细心的朋友可能注意到了在12.2中oracle alert日志的时间格式显示发生了改变,根据对oracle的理解,一般新特性有event或者参数进行控制的,通过分析确定是由于UNIFORM_LOG_TIMESTAMP_FORMAT进行控制的

2018-06-13T19:52:30.014659+08:00
RFS[21]: Selected log 12 for T-1.S-5589 dbid 1787743346 branch 957530932
2018-06-13T11:52:30.473314+00:00
Archived Log entry 5178 added for T-1.S-5582 ID 0x6a8e9d72 LAD:1

UNIFORM_LOG_TIMESTAMP_FORMAT修改为false

[oracle@xff ~]$ ss
SQL*Plus: Release 12.2.0.1.0 Production on Wed Jun 13 19:52:59 2018
Copyright (c) 1982, 2016, Oracle.  All rights reserved.
Connected to:
Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production
SQL> show parameter UNIFORM_LOG_TIMESTAMP_FORMAT ;
NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
uniform_log_timestamp_format         boolean     TRUE
SQL> alter system set uniform_log_timestamp_format=false;
System altered.

验证UNIFORM_LOG_TIMESTAMP_FORMAT=false效果

018-06-13T19:53:16.374197+08:00
RFS[19]: Selected log 14 for T-1.S-5120 dbid 1787743346 branch 957530932
2018-06-13T11:53:16.782388+00:00
Archived Log entry 5181 added for T-1.S-5117 ID 0x6a8e9d72 LAD:1
2018-06-13T19:53:19.797345+08:00
RFS[18]: Selected log 11 for T-1.S-5121 dbid 1787743346 branch 957530932
2018-06-13T11:53:20.268621+00:00
Archived Log entry 5182 added for T-1.S-5118 ID 0x6a8e9d72 LAD:1
Wed Jun 13 19:53:35 2018
ALTER SYSTEM SET uniform_log_timestamp_format=FALSE SCOPE=BOTH;
Wed Jun 13 11:53:37 2018
Wed Jun 13 19:53:37 2018
RFS[21]: Selected log 13 for T-1.S-5596 dbid 1787743346 branch 957530932
Wed Jun 13 11:53:38 2018
Archived Log entry 5183 added for T-1.S-5589 ID 0x6a8e9d72 LAD:1

UNIFORM_LOG_TIMESTAMP_FORMAT修改为true

SQL> alter system set uniform_log_timestamp_format=true;
System altered.
SQL>

验证UNIFORM_LOG_TIMESTAMP_FORMAT=true效果

Wed Jun 13 11:54:07 2018
Media Recovery Waiting for thread 1 sequence 5122 (in transit)
Wed Jun 13 11:54:07 2018
Recovery of Online Redo Log: Thread 1 Group 10 Seq 5122 Reading mem 0
  Mem# 0: /u01/app/oracle/oradata/xifenfei/std_redo10.log
2018-06-13T19:54:23.396030+08:00
ALTER SYSTEM SET uniform_log_timestamp_format=TRUE SCOPE=BOTH;
2018-06-13T11:54:24.597999+00:00
2018-06-13T19:54:24.615045+08:00
RFS[21]: Selected log 11 for T-1.S-5601 dbid 1787743346 branch 957530932
2018-06-13T11:54:25.054848+00:00
Archived Log entry 5187 added for T-1.S-5596 ID 0x6a8e9d72 LAD:1