IBM VERSION 9 Manual Do Utilizador
Protect
your
data
by
planning
and
implementing
a
disaster
recovery
strategy
for
your
system.
If
suitable
to
your
needs,
you
may
incorporate
the
automatic
database
backup
feature
as
part
of
your
backup
and
recovery
strategy.
If
the
database
is
enabled
for
roll-forward
recovery
(archive
logging),
then
automatic
database
backup
can
be
enabled
for
either
online
or
offline
backup.
Otherwise,
only
offline
backup
is
available.
Automatic
database
backup
supports
disk,
tape,
Tivoli
Storage
Manager
(TSM),
and
vendor
DLL
media
types.
Through
the
Configure
Automatic
Maintenance
wizard
in
the
Control
Center
or
Health
Center,
you
can
configure:
v
The
requested
time
or
number
of
log
pages
between
backups
v
The
backup
media
v
Whether
it
will
be
an
online
or
offline
backup.
If
backup
to
disk
is
selected,
the
automatic
backup
feature
will
regularly
delete
backup
images
from
the
directory
specified
in
the
Configure
Automatic
Maintenance
wizard.
Only
the
most
recent
backup
image
is
guaranteed
to
be
available
at
any
given
time.
It
is
recommended
that
this
directory
be
kept
exclusively
for
the
automatic
backup
feature
and
not
be
used
to
store
other
backup
images.
The
automatic
database
backup
feature
can
be
enabled
or
disabled
by
using
the
auto_db_backup
and
auto_maint
database
configuration
parameters.
In
a
partitioned
database
environment,
the
automatic
database
backup
runs
on
each
database
partition
if
the
database
configuration
parameters
are
enabled
on
that
database
partition.
Related
concepts:
v
“Developing
a
backup
and
recovery
strategy”
in
Data
Recovery
and
High
Availability
Guide
and
Reference
v
v
“Catalog
statistics”
in
Performance
Guide
v
“Table
and
index
management
for
MDC
tables”
in
Performance
Guide
v
“Table
and
index
management
for
standard
tables”
in
Performance
Guide
v
“Table
reorganization”
in
Performance
Guide
v
“Health
monitor”
in
System
Monitor
Guide
and
Reference
Related
reference:
v
“auto_maint
-
Automatic
maintenance
configuration
parameter”
in
Performance
Guide
Automatic
statistics
collection
The
DB2
optimizer
uses
catalog
statistics
to
determine
the
most
efficient
access
plan
for
any
given
query.
Having
out-of-date
or
incomplete
statistics
for
a
table
or
an
index
could
lead
the
optimizer
to
select
a
plan
that
is
not
optimal,
slowing
down
query
execution.
However,
deciding
which
statistics
to
collect
for
a
given
workload
is
complex,
and
keeping
these
statistics
up
to
date
is
time-consuming.
With
automatic
statistics
collection,
part
of
DB2’s
Automated
Table
Maintenance
feature,
you
can
let
DB2
determine
which
statistics
are
required
by
your
workload
and
which
statistics
need
to
be
updated.
With
automatic
statistics
collection
36
Getting
started
with
DB2
installation
and
administration