Oracle: Disable Archive log mode

Launch SQLPLUS and login as SYS

Determine if the database is setup in archive log mode

SQL> Select log_mode from v$database

SQL> archive log list;

Archive log list gives a little bit detailed information about your archive log setup. By default, when you enable archive log, all the archive log files are written into flash_recovery_area.Below command will show you the OS path

sql> show parameter recovery_file_dest

To Disable Archive log
SQL> shutdown immediate
SQL> startup mount
SQL> alter database noarchivelog
SQL> alter database open
SQL> archive log list

Your database is now running in NO archive log mode

Oracle: Enable Archive log mode

Launch SQLPLUS and login as SYS

Determine if the database is setup in archive log mode

SQL> Select log_mode from v$database

SQL> archive log list;

Archive log list gives a little bit detailed information about your archive log setup. By default, when you enable archive log, all the archive log files are written into flash_recovery_area.Below command will show you the OS path

SQL> show parameter recovery_file_dest

To Enable Archive log
SQL> shutdown immediate
SQL> startup mount
SQL> alter database archivelog
SQL> alter database open
SQL> archive log list

Your database is now running in archive log mode

Oracle: Import 11g data dump into 10g

You can use Oracle data dump to export data dump from 11g server, and import into 10g using the data Pump parameter called Version. When you use Version, Datapump exports all objects that are compatible for your target version

So, If your database is 11g and you want to export 11g and import into 10g

from 11g db cmd promt> expdp Test_schema_name/passs directory=datapump schemas=Test_Schema_Name Version=10.2.0.4.0

Once the export is done, you do the regular import from 10g server.