Memory bandwidth is a bottleneck for very large database machines. Par
allel-access three-dimensional two-photon memories have the potential
of achieving enormous throughput (>100 Gbit/s) and capacity (1 Tbit/cm
(3)) [Appl. Opt. 29, 2058 (1990)] and, consequently, are well suited f
or this application. Our analysis shows that some operations can be co
mpleted more than 2 orders of magnitude faster with this type of memor
y than with a system based on serial-access storage. These particular
memories have a further feature of being accessible in orthogonal dire
ctions. We show that this property, used in conjunction with a three-d
imensional data-organization scheme designed for this approach, leads
to improved performance by permitting the user a choice of accessing s
trategies for a given operation. (C) 1997 Optical Society of America.