In this talk, we present the use of PaStiX sparse direct solver in a Schwarz method for solving the frequencydomain Maxwell equations discretized by a high order HDG method. More precisely, the sparse solver is used to solve a system on sub-domains while iterative refinement is performed to get the global solution. Recently, low-rank compression have been added to PaStiX in order to reduce the time-to-solution or the memory footprint of the solver. The resulting low-rank solver can be used either as a direct solver at a lower accuracy or as a good preconditionner for iterative methods. We will investigate the use of low-rank compression for the frequency-domain Maxwell equations on large systems to experiment the compressibility of this equation.