misc fixed and TREND and reduce functionality by
[rrdtool.git] / doc / rrdgraph_data.src
index 88ac260..1f8fcb7 100644 (file)
@@ -2,7 +2,7 @@
 
 =head1 SYNOPSIS
 
-B<DEF:>I<E<lt>vnameE<gt>>=I<E<lt>rrdfileE<gt>>:I<E<lt>ds-nameE<gt>>:I<E<lt>CFE<gt>>[:step=I<E<lt>stepE<gt>>][:start=I<E<lt>timeE<gt>>][:end=I<E<lt>timeE<gt>>]
+B<DEF:>I<E<lt>vnameE<gt>>=I<E<lt>rrdfileE<gt>>:I<E<lt>ds-nameE<gt>>:I<E<lt>CFE<gt>>[:step=I<E<lt>stepE<gt>>][:start=I<E<lt>timeE<gt>>][:end=I<E<lt>timeE<gt>>][:reduce=I<E<lt>B<CF>E<gt>>]
 
 B<VDEF>:I<vname>=I<RPN expression>
 
@@ -18,7 +18,7 @@ a language called B<RPN> which is described in its own manual page.
 
 =head1 DEF
 
-B<DEF:>I<E<lt>vnameE<gt>>=I<E<lt>rrdfileE<gt>>:I<E<lt>ds-nameE<gt>>:I<E<lt>CFE<gt>>[:step=I<E<lt>stepE<gt>>][:start=I<E<lt>timeE<gt>>][:end=I<E<lt>timeE<gt>>]
+B<DEF:>I<E<lt>vnameE<gt>>=I<E<lt>rrdfileE<gt>>:I<E<lt>ds-nameE<gt>>:I<E<lt>CFE<gt>>[:step=I<E<lt>stepE<gt>>][:start=I<E<lt>timeE<gt>>][:end=I<E<lt>timeE<gt>>][:reduce=I<E<lt>B<CF>E<gt>>]
 
 This command fetches data from an B<RRD> file.  The virtual name
 I<vname> can then be used throughout the rest of the script. By
@@ -39,6 +39,11 @@ a resolution of 1800 seconds per B<CDP>, you should create an
 image with width 400 and time span 400*1800 seconds (use appropriate
 start and end times, such as C<--start end-8days8hours>).
 
+If consolidation needs to be done, the B<CF> of the B<RRA> specified in the
+B<DEF> itself will be used to reduce the data density.  This behaviour can
+be changed using C<:reduce=I<E<lt>B<CF>E<gt>>>.  This optional parameter
+specifies the B<CF> to use during the data reduction phase.
+
 Example:
 
         DEF:ds0=router.rrd:ds0:AVERAGE