Fujitsu UDS/SQL V2.5 Manual Do Utilizador
Schema DDL
Types of access
U929-J-Z125-9-76
93
D
ok
us
c
h
abl
on
en
1
9x
24 V
e
rs
ion
7
.3
us
f
ü
r F
ram
eM
ak
er
V
7
.x
v
o
m
1
4.
02
.2
00
7
©
c
o
gni
tas
Gm
b
H
20
01-
20
07
24
. Ok
tobe
r 20
07
S
ta
nd
0
9:
30
.2
3
P
fa
d:
G
:\
v
og
t\
fs
c
\ud
s
\M
anu
al
e
\e
n\
ud
s
e
nt
_e\
u
ds
ent
.k
0
4
Defining a secondary key for direct access via table
SEARCH KEY IS item-name,... USING INDEX [NAME IS name]
DUPLICATES ARE[ NOT] ALLOWED
DUPLICATES ARE[ NOT] ALLOWED
A key declared by SEARCH KEY IS... is a SEARCH key or secondary key. It may be made
up of more than one item.
up of more than one item.
item-name
specifies the item(s) comprising the key. All items must be part of the corre-
sponding record type.
name
specifies the name of the table. This name is referred to in the SSL statements
concerning the table.
DUPLICATES ARE [NOT] ALLOWED specifies whether UDS/SQL is to accept or reject
duplicate key values.
duplicate key values.
Based on this definition, UDS/SQL sets up a record SEARCH key table. This table contains
the values of the secondary keys of all records of a record type, representing a unique
reference between key value, database key value and physical address of the record. The
physical address is not automatically updated, however, when the position of the record is
changed.
A SEARCH key table is used only for direct access to the records of a record type. It always
involves several levels in order to speed up access.
the values of the secondary keys of all records of a record type, representing a unique
reference between key value, database key value and physical address of the record. The
physical address is not automatically updated, however, when the position of the record is
changed.
A SEARCH key table is used only for direct access to the records of a record type. It always
involves several levels in order to speed up access.
Several independent secondary keys can be defined for one record type.