All language subtitles for [SubtitleTools.com] RMAN Backups - Learning Oracle 12c [Video]

In this lesson,
we're going to learn

how to perform an RMAN backup.

So in order to do this,
first and foremost,

we need to log into RMAN.

So we simply launched
this from the command line

with the rman command.

Then we need to connect
to the database.

So we say, connect target.

So right now, our
database is open.

And our database is
also in ARCHIVELOG mode.

So it's important here to
talk about the difference

when we're doing backups between
hot backups and cold backups.

So a hot backup will occur when
the database is up and being

used by users, or
certainly can be,

and a cold backup would be
when the database is not

available for users.

If we're running in
NOARCHIVELOG mode,

we must back up
the database cold.

We cannot run a hot backup.

And that's one of the
reasons that ARCHIVELOG mode

is so important.

So if we are in
ARCHIVELOG mode, then we

can back up the database
while it's available.

Nevertheless, either way
one of the strengths of RMAN

is that the commands
to do the backups are

the same whether the
backup is cold or hot.

And so we can do a simple backup
is all we have to type in order

to back up whatever particular
entity we're interested in.

So we can back up
a datafile, back

up a tablespace with all of
its associated datafiles,

or we can back up
an entire database.

So let's try this by doing
a backup tablespace users.

Notice a few things
about the output here.

It says it's using the target
database control file instead

of a recovery catalog.

So the control file is
going to be the default

repository for datafile
information as far as

what's been backed up.

It's allocated a channel,
specifying a datafile

in the backup set.

Then it says it's
datafile number 00004,

gives us the location
for that datafile.

It says its starting
piece and finishing piece.

And a piece is the term for
a backup file, the data that

gets written out from a backup.

Then gives you the location
of the backup piece.

And notice that it's in
the Fast Recovery Area.

If we were to look in
our Fast Recovery Area,

we would see a folder for
BACKUPSET, the date, and then

the name of the backup
file that we have.

So to do a full
database backup, we

would only need to type
in backup database,

and hit Enter, and
allow it to run.

We can also do
backup datafile 4,

which is the same
datafile associated

with the user's tablespace.

Although we can interact
with RMAN in this really

interactive way, we can
also script our backups

to be a little more involved.

And to do that, we use
what's called a run block.

So we begin with the command
run, bracket, and then

our individual RMAN commands.

So by default, RMAN is
allocating a channel

to do work.

But we can do that
ourselves as well.

And we would do this if we
wanted more than one channel.

And sometimes we can
increase performance

by having more channels.

And we can say backup.

And in order to run
this, let's go ahead

and try a compressed backup.

So we could just simply
do backup database

and then close it
out, but we could also

say backup as compressed
backupset database, semicolon,

and then end the brace.

And so when we hit
Enter, Oracle is

going to run a full
backup of the database

and it's going to compress
the backup pieces on the fly.

And then the backup is complete.

And so it gives us
information as far as

where the backup
piece is located again

in our Fast Recovery Area, and
then shows that it's complete,

releases the channel, and
returns control back to us.

So RMAN, if we look back, can be
as simple as one-line commands

or more involved if we want
more control over our backup.