/usr/share/man/man3/ is in libgdbm-dev 1.8.3-13.1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/man/man3/gdbm.3.gz
/usr/share/man/man3/gdbm_errno.3.gz
/usr/share/man/man3/dbm_close.3.gz
/usr/share/man/man3/dbm.3.gz
/usr/share/man/man3/gdbm_store.3.gz
/usr/share/man/man3/dbmclose.3.gz
/usr/share/man/man3/gdbm_delete.3.gz
/usr/share/man/man3/dbminit.3.gz
/usr/share/man/man3/delete.3.gz
/usr/share/man/man3/gdbm_firstkey.3.gz
/usr/share/man/man3/gdbm_setopt.3.gz
/usr/share/man/man3/gdbm_close.3.gz
/usr/share/man/man3/dbm_open.3.gz
/usr/share/man/man3/fetch.3.gz
/usr/share/man/man3/dbm_pagfno.3.gz
/usr/share/man/man3/dbm_store.3.gz
/usr/share/man/man3/gdbm_nextkey.3.gz
/usr/share/man/man3/dbm_nextkey.3.gz
/usr/share/man/man3/gdbm_sync.3.gz
/usr/share/man/man3/dbm_delete.3.gz
/usr/share/man/man3/gdbm_reorganize.3.gz
/usr/share/man/man3/firstkey.3.gz
/usr/share/man/man3/dbm_fetch.3.gz
/usr/share/man/man3/gdbm_exists.3.gz
/usr/share/man/man3/dbm_firstkey.3.gz
/usr/share/man/man3/gdbm_open.3.gz
/usr/share/man/man3/dbm_dirfno.3.gz
/usr/share/man/man3/dbm_clearerr.3.gz
/usr/share/man/man3/gdbm_fetch.3.gz
/usr/share/man/man3/store.3.gz
/usr/share/man/man3/nextkey.3.gz
/usr/share/man/man3/dbm_rdonly.3.gz
/usr/share/man/man3/gdbm_error.3.gz
/usr/share/man/man3/dbm_error.3.gz
/usr/share/man/man3/gdbm_strerror.3.gz