/usr/lib/x86_64-linux-gnu/libdb.a is in libdb5.1-dev 5.1.25-11build1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libdb-5.1.a
/usr/lib/x86_64-linux-gnu/libdb-5.1.a