dbSNP variant IDs
I have two vcfs from D.melanogaster. The first contains in-house variant identifiers, the second contains NCBI-dbSNP variant identifiers. Only the first file contains the genotype data. There are 4 million variants in the first file and 5 million in the second. There is expected to be substantial overlap between the two in terms of what variants are present. How can I replace the in-house variant identifier with the dbSNP identifier for each corresponding variant ?