The Virtual Record Collection (vrc) acts as a front end
for a name sequenced record collection. Any records that
are modified using a vrc are kept in the vrc, while unmodified
records are accessed from the backend collection. The current
version of the vrc does not support access rights limitation
(order code 0 (rcweaken)), the unimplemented
functions ((rcntseg), (rctseg),
and (rcnseg) but supports all other
record collection calls (trc). VRC(kt==>X'217')
Virtual Record Collection Factory
VRCF(1+2*sizelimit;SB,M,SB,BACKEND==>;VRC)
Creates a new virtual record collection VRC. PSB,M,
and SB are as for normal factory invocations and BACKEND
is a key to the backend record collection. BACKEND should
allow read (rcread) and read user
data (rcreadud) operations.