/usr/share/gnunet/config.d/datacache.conf is in gnunet-server 0.9.3-7build1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 | [datacache-mysql]
DATABASE = gnunet
CONFIG = ~/.my.cnf
# USER = gnunet
# PASSWORD =
# HOST = localhost
# PORT = 3306
[datacache-postgres]
CONFIG = connect_timeout=10; dbname=gnunet
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