DM_OPENONCE_ALLOWREAD Keyword

10.1A

     DM_OPENONCE_ALLOWREAD={ON|OFF}

This keyword only takes affect when the Data Manager is executing with the 'open once' mode turned on. This keyword allows Data Manager files to be opened directly in READ ONLY mode by programs not using the Data Manager. This keyword replaces the DM_OPENONCE_SHARED keyword.

Note the following:

1. The default setting when this keyword is not used is the same as when 'DM_OPENONCE_ALLOWREAD=OFF'.

2. This keyword does not take affect if the 'DM_ONCEONCE=OFF' is used.

3. Only support by Windows OS Data Manager.

Detailed Behaviors

DM_OPENONCE_ALLOWREAD=OFF

1. The Data Manager opens data files with read/write access privileges.

2. The Data Manager locks the data files to prevent the possibility of changes to the managed data files by any third party Windows programs.

3. Plbwin runtimes must use the Data Manager to open managed data files. Otherwise, an appropriate I10 error occurs.

4. Windows Opportunistic Locking can be used by the Windows OS.

DM_OPENONCE_ALLOWREAD=ON

1. Data Manager data files are opened in exclusive mode.

2. Windows Opportunistic Locking is not used when an OS mapped drive is being used.

3. Plbwin runtimes can directly open data files using READ ONLY mode without using the Data Manager while the same files are opened by the Data Manager.

See Also: SUNDM Keywords, SUNADMIN, MAKEMFD