/usr/lib/mysql-testsuite/include/big_test.inc is in percona-server-test-5.6 5.6.22-rel71.0-0ubuntu4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 | --require r/big_test.require
disable_query_log;
eval select $BIG_TEST as using_big_test;
enable_query_log;
|