(PECL rrd >= 0.9.0)
rrd_tune — Tunes some RRD database file header options
$filename, array $options): boolChange some options in the RRD dabase header file. E.g. renames the source for the data etc.
filenameRRD database file name.
optionsOptions with RRD database file properties which will be changed. See rrd tune man page for details.
成功时返回 true, 或者在失败时返回 false。