To find the Last updated Data Set

[R_Win]

data x1;
input id sal ;
cards;
12 23
78 45
run;

data x2;
input id sal;
cards;
23 56
78 59
run;

data x3;
input id sal;
cards;
02 56
45 86
run;


data x_fin;
set x1 x3 x2;
run;

data x5;
input id sal;
cards;
02 56
45 86
run;


data x_fin;
set x1 x3 x2 x5 ;
run;


data x6;
input id sal;
cards;
02 56
45 86
run;

data x_fin;
set x1 x3 x2 x5 x6;
run;

i have created x_fin dataset by keeping x1,x2,x3 and after that i have added x5 and updated and after that i have added x6 to the dataset x_fin now.i want the dataset that was recently updated to x_fin and i should move that observations to a new dataset as x_updsets.so please help me out this is a example as Real time daily many datesets will come and set to one dataset now i want to find which dataset was added to it recently

[GertNissen]

Have a look at SASHELP.VTABLE and the columns modate and crdate.

Resources:
- Sample 25436: Demonstrates basic SQL DICTIONARY statements -> http://support.sas.com/kb/25/436.html
- Dictionary Tables and Views: Essential Tools for Serious Applications -> http://www2.sas.com/proceedings/sugi29/237-29.pdf
- An Introduction to SAS® Dictionary Tables -> http://www2.sas.com/proceedings/forum2007/235-2007.pdf