[petsc-users] how to reuse Mumps factorization

Hello, I am using Mumps to solve a problem with multiple time steps. The matrix structure does not change but its value may or may not change during those steps. That means I should reuse the symbolic factorization but recall numeric factorization when needed. I have found the following anwser of a similar question https://lists.mcs.anl.gov/pipermail/petsc-users/2020-August/041846.html which says "it automatically uses the same factorization", but I don't know if it includes numerical factorization also. My question is : 1. Does numeric factorization do automatically? If not 2. Could I control when numeric factorization should be done and how to do it? Much thanks YUAN