/usr/lib/x86_64-linux-gnu/libsoci_postgresql.so is in libsoci-dev 3.2.3-1ubuntu2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libsoci_postgresql.so.3.2
/usr/lib/x86_64-linux-gnu/libsoci_postgresql.so.3.2