On some machines, the TRY statement might be executed more quickly if you use the following limited form of the statement:

TRY [ <error procedure identifier> ] <procedure invocation or reference>

This limited form of the TRY statement provides more limited protection than the normal form. Unlike the normal form, the limited form does not begin to protect the process until the procedure begins execution. Thus, if an error occurs in passing parameters to the procedure, or if the procedure invoked is a null procedure reference, the process is not protected from the error. (However, on some machines the limited form does protect the process if the process invokes an imported procedure that is not available.

If the procedure fails to finish normally, the error procedure is automatically invoked. No protection is provided if the error procedure also fails to finish normally.