Question : Is there a limit to how many categories / points you can have in a chart in Reporting Services 2008

If I needed to plot a graph/chart of each day for the last year or last 2 years, will reporting services be able to handle more than 255 columns or points of data?   In short is there a limit to how many data points can be on a chart?

Answer : Is there a limit to how many categories / points you can have in a chart in Reporting Services 2008

I do not think that there is a hard and fast limit to the number of points that a Report Services 2008 graph will show. It just depends on how much data is in the dataset that the graph is based on.

The charts will identify the min and max on the axis and use an algorithm to create the points on the graph.

See the following web sites.

Formatting Axis Labels on a Chart
http://msdn.microsoft.com/en-us/library/bb934421.aspx

The chart calculates the minimum and maximum value along each axis based on the values in your result set. On the value axis, the scale will always be determined by the smallest and largest number in the value field. On the category axis, the minimum and maximum value types are determined depending on the type of your category field.

How to: Specify an Axis Interval
http://msdn.microsoft.com/en-us/library/bb934284.aspx

You can specify the number of intervals you want in the axis Interval property. Reporting Services calculates the number of intervals at run time, based on the data in the result set.

This topic is not applicable for date or time values on the category axis. By default, DateTime values appear as days.

So it should list the dates along the category axis, but I would expect the graph to use an algorithm to tidy up the data for the graph.