When the name of a DDM file is specified on the Allocate
Object (ALCOBJ) command on the source server, the command allocates
the DDM file on the source server and its associated file or file member on
a target server.
The command places locks on both the DDM file and the remote file
in each pair. (These files are locked on both servers to ensure that they
are not changed or deleted while the files or members are locked.) One
or more pairs of files (DDM files on the source server and remote files on
one or more target servers) can be allocated at the same time.
Each DDM file is always locked with a shared-read (*SHRRD) lock.
Shared-read is used for the DDM files regardless of the lock types that might
have been specified on the command to lock other local files at the same time.
The lock placed on the remote file depends on the type
of target server:
- When the target is an iSeries™ server or
a System/38™, the resulting locks
on the remote file are the same as if the file is a local database file. That
is, the iSeries or the System/38 remote file is also locked
with a shared-read lock, and the member (the one specified, or the first one)
is locked with the lock type specified on the command.
- When the target is not an iSeries server or
a System/38, the remote file
is locked with the specified lock type, except that some non-iSeries target
servers might use a stronger lock than was specified on the command. If an ALCOBJ command
specifies multiple DDM files, and one or more are on non-iSeries target
servers, those remote files are locked with the lock type specified on the
command. If a member name is specified for a remote server that does not support
members, the lock request is rejected with an error message, unless the member
name is the same as the DDM file name.