Specifies the level of shared access allowed to SAS data sets
| Language element: |
data set option
|
| Default: |
varies
|
| Engines: |
V6, V7, CONCUR
|
| Valid as: |
data set option
|
| OpenVMS specifics: |
syntax
|
-
MEM
-
demands exclusive access to the file.
-
REC
-
allows sharing of the file with record-level locking.
The CNTLLEV= data set option specifies the level at which shared update access to a SAS data set is
denied.
With the CONCUR engine, you can request exclusive access to the file, or you can share access with record-level
locking.
By default with the concurrency engine, data sets that are opened for input allow shared read access; data sets that are opened for output demand exclusive access;
and data sets that are opened for update either allow shared read and shared write access or they retain exclusive access to the file, depending on the method that is
used.
For example, you can allow other users both read and write access to a data set that you are opening for input only. By default, only shared read access is allowed.
To enable record-level locking for the data set TEST.TWO, use the following statements:
libname test concur '[mydir]';
data test.one;
set test.two(cntllev=rec);
run;
As another example, suppose you want to both plot and update your file simultaneously by using the FSEDIT procedure. By default, the
PLOT procedure opens a data set for exclusive access, even though it only reads the file. To allow concurrent access, use the following statements:
libname test concur '[mydir]';
proc plot data=test.a(cntllev=rec);
run;
Note:
The CNTLLEV= data set option is ignored for output files; output files always retain exclusive
access. ![[cautend]](../common/images/cautend.gif)
Copyright © 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.
