/usr/lib/x86_64-linux-gnu/libldb.so is in libldb-dev 2:1.1.24-1ubuntu3.1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libldb.so.1.1.24
/usr/lib/x86_64-linux-gnu/libldb.so.1.1.24