ORACLE - Data Guard - Switchover

How to perform switchover for Oracle Data Guard ?

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Verification before switchover:
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select switchover_status from v$database;
show parameter log_archive_dest_state
select sequence#, status, applied from v$archived_log;
alter system switch logfile;

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1)old primary site:
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SQL>alter database commit to switchover to physical standby with session shutdown;
SQL>shutdown immediate
SQL>startup nomount
SQL>alter database mount standby database;
SQL>alter system set log_archive_dest_state_2=defer scope=both;

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2)old standby site:
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SQL>select switchover_status from v$database;
SQL>alter database commit to switchover to primary;
SQL>shutdown immediate
SQL>startup

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3)New standby site - START MRP -
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SQL>alter database recover managed standby database disconnect from session;