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К этому устройству также есть другие инструкции:
Фрагмент инструкции
A
TT
A
CH
DBEn
vironmen
t.
F
or
an
example,
the
SQL
statement,
Select
*
from
SYSTEM.IMA
GEKEY,
after
connecting
to
the
DBEn
vironmen
t
will
display
all
hash
indices.
If
B-T
ree
indices
are
created
on
the
k
ey
items
of
the
selected
master
data
sets
using
DBUTIL
or
DBSCHEMA,
IMA
GE/SQL
en
ters
denitions
for
the
B-T
ree
indices
in
the
system
catalog
of
the
DBEn
vironmen
t.
Although
the
B-T
ree
index
can
only
b e
created
on
the
k
ey
item,
the
denitions
for
B-T
ree
indices
on
all
of
its
related
searc
h
items
of
the
detail
data
sets
are
also
en
tered
in
the
SQL
catalog.
The
B-T
ree
index
on
the
k
ey
item
of
the
master
set
is
p erceiv
ed
as
an
EXPLICIT
index
and
that
on
the
related
searc
h
item
as
IMPLICIT
(virtual).
F
or
an
example,
if
a
B-T
ree
index
is
created
on
the
k
ey
item
whic
h
has
paths
to
16
detail
data
sets,
a
denition
for
an
index
for
all
16
data
sets
will
b e
en
tered.
That
is,
this
will
result
in
to
17
(1
for
master
and
16
for
detail
data
sets
)
denitions.
The
index
on
the
k
ey
item
of
the
master,
except
for
P
and
Z
t
yp es,
is
en
tered
as
'unique'
index.
Other
denitions,
b
y
default,
are
non-unique.
The
index
name
for
the
k
ey
items
is
deriv
ed
b
y
suxing
its
mapp ed
column
name
with
'
B1'.
F
or
the
related
searc
h
item,
its
mapp ed
column
is
suxed
with
'
Vn'
where
n
is
the
path
n
um
b er.
With
B-T
ree
indices,
y
ou
can
use
op erators
suc
h
as
' <=',
and
' >
'
whic
h
are
p ermissible
in
ALLBASE/SQL.
The
B-T
ree
indices
can
b e
seen
in
the
views,
SYSTEM.INDEX
and
CA
T
ALOG.INDEX,
of
the
DBEn
vironmen
t.
If
the
k
ey
item
or
its
related
searc
h
item
is
split
using
the
SPLIT
command
of
IMA
GESQL,
denitions
for
b oth
hash
index
and
B-T
ree
index
on
the
split
item
will
not
b e
en
tered.
F
or
an
example,
a
k
ey
item
on
whic
h
a
B-T
ree
index
exists,
is
split,
but
its
related
searc
h
item
in
the
detail
set
is
not.
Denitions
for
unique
hash
index
and
unique
B-T
ree
index
on
this
split
k
ey
item
will
not
b e
en
tered.
Ho
w
ev
er,
denitions
for
non-unique
hash
index
as
w
ell
as
non-unique
B-T
ree
index
on
the
related
searc
h
item
will
b e
en
tered.
If
the
database
is
enabled
for
third-party
indices
(TPI),
A
TT
A
CH
en
ters
denitions
for
all
TPIs,
excluding
k
eyw
ord
indices
and
the
ones
for
whic
h
the
third-part
y
do es
not
pro
vide
information.
The
TPIs
are
en
tered
as
unique
or
non-unique
based
on
the
index
conguration
and
information
pro
vided
b
y
the
third-party
for
this
index.
While
k
eys,
searc
h
items,
and
B-T
ree
indices
are
registered
in
the
sp ecied
DBEn
vironmen
t,
third-party
indices
are
registered
in
all
attached
DBEn
vironmen
ts.
Multiple
index
denitions
on
the
same
column
can
co exist
and
the
SQL
optimizer
deriv
es
the
optimal
access
plan
based
on
the
statistics
presen
t
in
the
system
catalog.
In
other
w
ords,
the
k
ey
or
searc
h
item
of
the
set
can
ha
v
e
a
maximum
of
three
index
denitions.
One
will
b e
a
hash
index
denition
en
tered
automatically
at
A
TT
A
CH
time,
another
can
b e
a
B-T
ree
index
denition,
and
the
third
can
b e
a
third-party
index
denition.
It
is
recommended
that
b oth
B-T
ree
4-6
IMA
GE/SQL
Utility
Commands
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