CUR_SCN_COMPAT 2019年6月23日自动从1直接跳级到3

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我是靠谱客的博主成就便当，最近开发中收集的这篇文章主要介绍CUR_SCN_COMPAT 2019年6月23日自动从1直接跳级到3，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

[oracle@zyjxnew ~]$ sqlplus /nolog

SQL*Plus: Release 11.2.0.4.0 Production on Wed Jul 3 09:39:59 2019

SQL> conn /as sysdba
Connected.
SQL> !vi scn_chk.sql

set serveroutput on
declare
rsl number;
headroom_in_scn number;
headroom_in_sec number;
CUR_SCN_COMPAT number;
MAX_SCN_COMPAT number;
auto_rollover_ts date;
target_compat number ;
is_enabled boolean;
VERSION varchar2(100);
is_rolloverd boolean;
db_role varchar2(100);
started_ts date;
begin
select banner into VERSION from v$version where rownum=1;
select DATABASE_ROLE into db_role from v$database;
select startup_time into started_ts from v$instance;
dbms_scn.GETCURRENTSCNPARAMS(rsl,headroom_in_scn,HEADROOM_IN_SEC,CUR_SCN_COMPAT,MAX_SCN_COMPAT);
dbms_output.put_line('Current datatime:'||to_char(sysdate,'RRRRmmdd hh24:mi:ss'));
dbms_output.put_line('Oracle Version:'||VERSION);
dbms_output.put_line('Database role:' ||db_role);
dbms_output.put_line('Instance starttime: '||to_char(started_ts,'RRRRmmdd hh24:mi:ss'));
dbms_output.put_line('RSL=' ||rsl);
dbms_output.put_line('headroom_in_scn=' || headroom_in_scn);
dbms_output.put_line('headroom_in_sec=' || headroom_in_sec);
dbms_output.put_line('CUR_SCN_COMPAT=' ||CUR_SCN_COMPAT);
dbms_output.put_line('MAX_SCN_COMPAT=' ||MAX_SCN_COMPAT);

dbms_scn.getscnautorolloverparams (auto_rollover_ts, target_compat, is_enabled);
dbms_output.put_line( 'auto_rollover_ts='|| to_char(auto_rollover_ts, 'YYYY-MM-DD' ));
dbms_output.put_line( 'target_compat='||target_compat);
if(is_enabled) then
dbms_output.put_line(' Auto_rollover is enabled!' );
if CUR_SCN_COMPAT = target_compat then
dbms_output.put_line('SCN compat had Auto rollover !' );
end if;
if CUR_SCN_COMPAT < target_compat and sysdate > auto_rollover_ts then
dbms_output.put_line('SCN compat No Auto_rollover !' );
-- standby or read-only database
if started_ts<auto_rollover_ts and db_role='PHYSICAL STANDBY' then
dbms_output.put_line('Tip: Restart Instance SCN compat will rollover automatic.' );
end if;
end if ;
else
dbms_output.put_line( ' Auto_rollover is disabled!');
end if;
end;
/
"scn_chk.sql" [New] 49L, 1950C written

SQL> @scn_chk.sql
Current datatime:20190703 09:40:24
Oracle Version:Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit
Production
Database role:PRIMARY
Instance starttime: 20190527 18:48:28
RSL=35577937002496
headroom_in_scn=19759203047497
headroom_in_sec=201001007
CUR_SCN_COMPAT=3
MAX_SCN_COMPAT=3
auto_rollover_ts=2019-06-23
target_compat=3
Auto_rollover is enabled!
SCN compat had Auto rollover !

PL/SQL procedure successfully completed.
SQL> col CURRENT_SCN for 999999999999999999999999999999
SQL> select current_scn from v$database;

CURRENT_SCN
-----------
15818733980592

SQL> @scn_chk.sql
Current datatime:20190703 09:45:50
Oracle Version:Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit
Production
Database role:PRIMARY
Instance starttime: 20190527 18:48:28
RSL=35577969049600
headroom_in_scn=19759235066349
headroom_in_sec=201001333
CUR_SCN_COMPAT=3
MAX_SCN_COMPAT=3
auto_rollover_ts=2019-06-23
target_compat=3
Auto_rollover is enabled!
SCN compat had Auto rollover !