NET/MASTER Management Services (MS) Command Reference Manual
LBANNER
UDBCTL OPEN
NonStop NET/MASTER MS Commands
115412 Tandem Computers Incorporated 2–577
UDBCTL OPEN The UDBCTL OPEN command opens a file or a pair of related files as a user database
(UDB) or UDB pair, respectively. This command does not create the file(s); the file(s)
must exist before being opened (the FUP CREATE command from TACL, for example,
creates a file).
This command opens the file or pair of files for access by NonStop NET/MASTER MS
processes. This is a shared open: many NonStop NET/MASTER MS processes can
open the file or pair of files, but no other process can lock the file or pair of files
exclusively. You can open a file or pair of files as a UDB or UDB pair, respectively,
once only.
NCL works with UDBs and UDB pairs. After a file or pair of files is opened for access
by NonStop NET/MASTER MS and it has a UDB identifier (UDB ID), an NCL process
can open the UDB or UDB pair using the FILE OPEN verb. Entry-sequenced files, key-
sequenced files, edit files, and processes are all regarded as UDBs by NCL.
The two files in a UDB pair are treated as a single logical file in all file processing
operations. You can open only key-sequenced files in a UDB pair. The value of the
record length, primary key length, and primary key offset must be identical;
additionally, the value of the primary key offset must be zero. The key length and key
offset of alternate keys, if present, must be identical.
UDBCTL OPEN={
file-spec
| (
file-spec
,
file-spec
) }
[ ID={
udb-id
| * } ]
[ ACCESS={ RANDOM | SEQUENTIAL | SYSTEM } ]
[ BUFFERED ]
[ INPUT | RESET ]
[ RECSIZE=
buffer-size
]
[ SEQUENTIALBUFFERING={ NONSHARED | SHARED } ]
[ SWGUID={ YES | NO [ TYPE=PERMANENT ] } ]
file-spec
:
[ \
sys
. ][ $
volume
. ][
subvolume
. ]
file-name
file-spec
specifies the name of the file to open.
(
file-spec
,
file-spec
)
specifies a pair of files to open. Both files must be key-sequenced. The first file in
the pair is opened for read/write access; the second file in the pair is opened for
read-only access.
ID
assigns a unique UDB ID to the UDB or UDB pair when it is opened.