/usr/lib/x86_64-linux-gnu/liblua5.1-sql-postgres.so.2 is in liblua5.1-sql-postgres-2 2.2.0~rc1-5.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/liblua5.1-sql-postgres.so.2.0.0