docs.datacontroller.io/docs/cas-tables.md

layout, title, description, og_image

layout	title	description	og_image
article	CAS Tables	Dealing with CAS (in-memory) Tables in Data Controller	/img/SAS-Viya-and-CAS-300x249.png

!!! warning Work in Progress!

CAS Tables

CAS Tables require special consideration in Data Controller with regards to the following topics:

• System Account
• Loading
• Unloading
• Special Variables

System Account

Despite having a shared SYSUSERID, the SPRE session will (by default) authenticate using the logged-in user credentials. To get around this, it is necessary to set up the CAS connection in the autoexec - ie, before the user takes over the session. The code snippet will be:

%let _CASHOST_ = <your-host>;

%let _CASPORT_ = 5570;

cas dcsession authdomain="<your-domain>" sessopts=(caslib=casuser);

The credentials need to be first placed in the viya credentials service as described here.

Another approach can be to use the `AUTHINFO="authentication-file" option, as described here.

Note that since the CAS connection is using a shared account, the CASUSER library is never shown in the DC interface.

Loading

It can happen that a CAS table is configured in Data Controller but not loaded into memory. In this case, when a user selects the table, it will be automatically loaded.

Unloading

After an approval, the in-memory version of the CAS Table will be updated. To apply this to the underlying file on disk, the following code must be executed (eg in a POST APPROVE HOOK):

proc casutil;
   save casdata="mytable" incaslib="mycaslib"
        casout="mytable" outcaslib="mycaslib"
        replace;
quit;

Special Variables

Processing of data in Data Controller is performed in SPRE with SAS datasets - and as such, it is not possible to process character variables longer than 32k or other CAS specific data types.