17, RMAN can create a database. This is a useful capability, but the new database can
be only on the same platform as the source database; the technique leverages RMAN
backup and restore, which cannot work across platforms. The transportable database
feature leverages the transportable tablespace capability, which can go across platforms.
The technique is to copy all the datafiles to the new machine with appropriate
conversion, start an instance with a new parameter file, and create a new controlfile
and online log files.
Transporting a database from one machine (and possibly one platform) to another
does not involve any technology not already discussed in this chapter and previous
chapters on backup and recovery, but it does involve many steps. To ease the process,
there is an RMAN command that will automate (almost) the whole process: it will
convert the datafiles, generate a parameter file, and generate a script to be run on the
destination machine that will create the controlfile and open the database with a
RESETLOGS (necessary to create the online redo log files). The script will not, however,
transfer any files that are external to the database (such as BFILEs or external table
files), and it will not create a password file.
TIP After a database transport there will usually be some objects that must
be adjusted manually, such as directories. Also, the transported database will
have the same DBID as the source: you can change this with the DBNEWID
utility, implemented as the executable $ORACLE_HOME/bin/nid on Unix
or %ORACLE_HOME%\bin\nid.exe on Windows.
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