Difference between library pre-asigned by external configuration and not pre-asigned library

[DmitryErshov]

Could you please clarify difference between library pre-asigned by external configuration and not pre-asigned library.

According to this article:

The third and final option for pre-assigning libraries (pre-asigned by external configuration) is to use an external definition or an autoexec file. This method essentially makes the library available to client applications but moves the code out of the user interface to an external file.

But what if I don't pre-assigne library and use LIBNAME statement in autoexec file to assign it. It seems like it is absolutely similar to make library pre-asigned by external configuration.In both cases I can write LIBNAME instruction in autoexec file and get similar results.

Am I right? Or I don't see some difference. 

[jklaverstijn · Accepted solution]

If you define your library as not pre-assigned clients like DIS will include a libname statement in the generated code. This code will be executed after the autoexec so it will overrule it. Defining the lib pre-assigned by external configuration will prevent that.

In essence this difference is what "but moves the code out of the user interface to an external file" refers to.

Hope this helps,

-- Jan.