We generally create alias for datasets with the command.

DEFINE ALIAS(ABC.LOAD) REALATE(ABC.V1.LOAD) -- so when ever we refer to ABC.LOAD we get to access ABC.V1.LOAD.

In case we want to change the alias to point o ABC.V2.LOAD -- the only way to do it delete the alias and redefine it.

We can us SYMBOLICRELATE with DEFINE alias to avoid that situation DEFINE ALIAS(ABC.LOAD) SYMBOLICRELATE(ABC.&VER..LOAD) -- so when ever we refer to ABC.LOAD it refers to ABC.&VER..LOAD and we need have the &VER. value provided in IEASYMxx. so it picks up ABC.V1.LOAD.

Incase you want to change the alias to point to ABC.V2.LOAD -- then we can update

IEASYMxx to have &VER. = V2 and issue the command

SETLOAD xx,IEASYM,DSN=SYSx.IPLPARM,VOL=xxxxxx

(xx is the LOADxx and xxxxxx is sysx.iplparm volume) .. this command dynamically updates symbols and all you aliases would point to ABC.V2.LOAD this is without IPL.

If we are doing with an IPL then just update IEASYSMxx and IPL.