  We present an implementation for the use of Cholesky decomposition (CD) of
two-electron integrals within the spin-free Dirac-Coulomb (SFDC) scheme that
enables to perform high-accuracy coupled-cluster (CC) calculations at costs
almost comparable to those of their non-relativistic counterparts. While for
non-relativistic CC calculations atomic-orbital (AO) based algorithms, due to
their significantly reduced disk-space requirements, are the key to efficient
large-scale computations, such algorithms are less advantageous in the SFDC
case due to their increased computational cost on that case. Here,
molecular-orbital (MO) based algorithms exploiting the CD of the two-electron
integrals allow to reduce disk-space requirements, and lead to computational
cost in the CC step that are more or less the same as in the non-relativistic
case. The only remaining overhead in a CD-SFDC-CC calculation are due to the
need to compute additional two-electron integrals, the somewhat higher cost of
the Hartree-Fock calculation in the SFDC case, and additional cost in the
transformation of the Cholesky vectors from the AO to the MO representation.
However, these additional costs typically amount to less than 5-15 % of the
total wall time and are thus acceptable. We illustrate the efficiency of our CD
scheme for SFDC-CC calculations on a series of illustrative calculations for
the X(CO)$_4$ molecules with X = Ni, Pd, Pt.
