IBM Frozen Dessert Maker VERSION 9 Manual De Usuario
Chapter
6.
Automatic
maintenance
Your
DB2
product
provides
automatic
maintenance
capabilities
for
performing
database
backups,
and
keeping
statistics
current
as
necessary.
Automatic
database
backup
provides
users
with
a
solution
to
help
ensure
their
database
is
being
backed
up
both
properly
and
regularly,
without
either
having
to
worry
about
when
to
back
up,
or
having
any
knowledge
of
the
backup
command.
Automatic
statistics
collection
attempts
to
improve
the
performance
of
the
database
by
maintaining
up-to-date
table
statistics.
The
goal
is
to
allow
the
optimizer
to
choose
an
access
plan
based
on
accurate
statistics.
Automatic
statistics
profiling
advises
when
and
how
to
collect
table
statistics
by
detecting
outdated,
missing,
and
incorrectly
specified
statistics
and
by
generating
statistical
profiles
based
on
query
feedback.
Enablement
of
the
automatic
maintenance
features
is
controlled
using
the
automatic
maintenance
database
configuration
parameters.
These
are
a
hierarchical
set
of
switches
to
allow
for
simplicity
and
flexibility
in
managing
the
enablement
of
these
features.
The
Configuration
Advisor
runs
automatically
when
you
create
a
database
in
DB2
Version
9.
This
autonomic
computing
feature
provides
significant
performance
improvement
to
newly
created
databases,
and
causes
little
overhead
to
the
system.
Also
when
you
create
a
database
in
DB2
Version
9,
AUTOMATIC
STORAGE
is
enabled
by
default.
Automatic
storage
simplifies
storage
management
by
allowing
you
to
specify
storage
paths
where
the
database
manager
can
place
table
space
data,
and
where
the
database
manager
allocates
space
for
various
uses.
Self
tuning
memory
is
enabled
by
default,
this
autonomic
feature
simplifies
the
task
of
memory
configuration
by
automatically
setting
values
for
memory
configuration
parameters
and
sizing
buffer
pools.
When
enabled,
the
memory
tuner
dynamically
distributes
available
memory
resources
between
several
memory
consumers
including
sort,
package
cache
and
lock
list
areas
and
buffer
pools.
Automatic
database
backup
A
database
may
become
unusable
due
to
a
wide
variety
of
hardware
or
software
failures.
Automatic
database
backup
simplifies
database
backup
management
tasks
for
the
DBA
by
always
ensuring
that
a
recent
full
backup
of
the
database
is
performed
as
needed.
It
determines
the
need
to
perform
a
backup
operation
based
on
one
or
more
of
the
following
measures:
v
You
have
never
completed
a
full
database
backup
v
The
time
elapsed
since
the
last
full
backup
is
more
than
a
specified
number
of
hours
v
The
transaction
log
space
consumed
since
the
last
backup
is
more
than
a
specified
number
of
4
KB
pages
(in
archive
logging
mode
only).
©
Copyright
IBM
Corp.
1993,
2006
35