Sigma users sometimes run into the following error while building visualizations:
“This chart is incomplete. It had more than 25,000 points. Try aggregating columns.”
In this how-to, we’ll walk through what causes this error as well as how to avoid it.
What causes this error?
Sigma visualizations can build charts off of millions or billions of rows of raw data. You can view this underlying data by Maximizing Element.
You can see that the visualization in the example below is being built off of ~4.5 millions rows of raw data
However, Sigma Visualizations have a graphical limitation on the number of individual points that can be visualized on a chart at a single time.
By points, we mean individual bars, scatter points, pie slices, line points etc.
In the example below, the blue bar that has been circled on this bar chart is a single point on the chart. It is a visual representation of the circled value in the underlying table.
There are 102 such values in the underlying table, and therefore 102 points visualized on this chart.
(We will expand on this in more detail in the next section.)
If we create a chart which has more than 25,000 individual points visualized … we can reliably expect to see this error message
How can we avoid this error?
We can work around this limitation by reconfiguring our element to aggregate our data by lower cardinality columns, until we have fewer than 25,000 points on our chart.
In Sigma, visualizations are built off of an underlying table of data that can be accessed by Maximizing your element. This underlying table has groupings and calculations just like a typical Table element, but determined by the columns in your configuration fields on the left.
If you have Aggregate Values enabled for your chart, then the columns that correspond to your individual points on your chart will be located here in the lowest grouping level of this underlying table.
The values in these columns are aggregates of your raw data, and each value in these columns represents an individual point on your chart.
Returning to our simpler previous example, this chart has 102 values in the lowest grouping level, and therefore 102 points visualized on the chart
However, in our current example, the chart has ~1.6 million values in the lowest grouping level, and therefore ~1.6 million points visualized on the chart … which is well above our 25,000 point limit.
To work around this limitation, we need to lower this number.
We can either do this by applying a filter to our chart to reduce the total number of points …
Or, we can change our column selection. If we select columns with lower cardinality (meaning, fewer distinct values) … then we will have fewer points on our chart.
Note that if you do not have Aggregate Values checked, then the individual points on your chart will be built directly off your raw data, without any aggregations being done.
This will increase the total number of chart features.
If you have Aggregate Values unchecked and you’re hitting this error, I would strongly recommend attempting to aggregate to reduce your total number of points.
Otherwise, you will have to use filters very aggressively to get under the 25,000 point limit.
Hopefully this guide has been helpful to you, and you now feel equipped to take full advantage of Sigma’s visualizations!
If you have any thoughts or questions on this, please don’t hesitate to let us know in the comments!
Take care and happy charting!
-Chandler Phelps, Sigma Support