A libname statement can be assigned to cover a collection of other libnames (or a list of directories). So a proc copy could transcribe all the datasets in a collection of libraries (each listed in the "aggregate" library) to a destination library. Here's an example:
libname sdat1 'c:\temp\sasdata1';
libname sdat2 'c:\temp\sasdata2';
data sdat1.class; set sashelp.class; run;
data sdat2.cars; set sashelp.cars; run;
libname srclibs (sdat1 sdat2);
libname tmp 'c:\temp';
proc copy out=tmp in=srclibs ;
run;
The log reports copying both datasets, one from each SDATx library, to the TMP library.
418 libname srclibs (sdat1 sdat2);
NOTE: Libref SRCLIBS was successfully assigned as follows:
Levels: 2
Engine(1): V9
Physical Name(1): c:\temp\sasdata1
Engine(2): V9
Physical Name(2): c:\temp\sasdata2
419 libname tmp 'c:\temp';
NOTE: Libref TMP was successfully assigned as follows:
Engine: V9
Physical Name: c:\temp
420 proc copy out=tmp in=srclibs ;
421 run;
NOTE: Copying SRCLIBS.CARS to TMP.CARS (memtype=DATA).
NOTE: There were 428 observations read from the data set SRCLIBS.CARS.
NOTE: The data set TMP.CARS has 428 observations and 15 variables.
NOTE: Copying SRCLIBS.CLASS to TMP.CLASS (memtype=DATA).
NOTE: There were 19 observations read from the data set SRCLIBS.CLASS.
NOTE: The data set TMP.CLASS has 19 observations and 5 variables.
NOTE: PROCEDURE COPY used (Total process time):
real time 0.01 seconds
cpu time 0.01 seconds
I have no idea whether this behavior is replicated when reading from a collection of XPORT-engine libraries.
Also: if a dataset name appears in multiple locations in the "collective" library, then, in my experience, only the first one (i.e. the leftmost library) is accessed.
