crystal's limitations: some information you need to know
As an admin user, you need to be aware of the many possibilities that crystal offers, and, at the same time, of some limitations that our product might have.
A deep knowledge of crystal allows our users to make the most of the experience.
Let’s see together what the limitations of crystal are, broken down by area, and remember we are constantly working to improve our product: check out the Release notes section for more info!
The automated forecasting feature is working only for topics with the over time objective and single line visualization, without key values.
Note that this feature is compatible only with over time topics with monthly and daily time aggregation.
This feature requires at least 18 points for monthly data and 270 points for daily data.
Automated forecasting can forecast values in the future up to 12 points for monthly data and 60 points for daily data, depending on the number of data points.
This feature requires at least 80% of points to be non-missing for monthly data and 70% of points for daily data.
The automated forecasting model does not consider the first and the last points if the metric aggregation function is sum or count. This is because these points for a monthly or daily topic could contain only partial data. For example, if we have data only for the first half of the last month, the chart would show a dip there, which might ruin the prediction.
Suggestion tips served at each time will always contain different topics.
Our recommender system cannot suggest tips consisting of a common topic with different filters or filter values.
If for example we'd have:
Show me total sum of revenues in July 2021
Show me total sum of revenues in the region of Milano
Show me total sum of revenues for Milan branch in July 2021
The system will show only one of the above three sentences which technically are related to the same topic.
crystal app (Web/iOS/Android advisor)
The feature for the Dashboard, filter persistence, works on the section filters, meaning that the filter will be remembered through multiple sessions, but it is currently not saving the time range.
Filter values update
At the moment, the filter values are updated only during the publication or depublication of a topic. There’s no automated way to update the filter values without a training action.
The comparison objective normally doesn’t support a request without the specification of the objective or the breakdown. In other words, you are specifically requested to formulate your question by openly mentioning the comparison, for example by saying: “show me the comparison between products sold this year and last year”.
Disambiguationat the single entity level is not supported at the moment.
Let’s see an example:
If Entity A is “Enterprise Sales” (topic → Total Enterprise Sales)
and Entity B is “Atomic Sales” (topic → Total Atomic Sales)
If the question is: “Total sales in 2020”, the answer will return one value only, either Entity A or Entity B, but not both.
Note that crystal supports the connection to data sources with TLS >= 1.2.
Complex fields types
At the moment crystal is not supporting complex fields like “Json objects“ for Postgres or “LOB“ for Oracle. If in a table such field types are present, crystal will not be able to use them in the topic configuration process, nor will she be able to preview the related data.
Note that, for Oracle, all the data types described here that are not present in the above list are not supported.
Complex fields names
There are some restrictions on the use of special characters and punctuation signs in some fields, and in particular:
crystal doesn’t support column names that contain special characters like .(),%$… . The presence of a special symbol inside a column name is causing the failure of the topic retrieval.
crystal doesn’t support periods inside the schema name.
crystal doesn’t support column names that include "/" for dynamic filters.
As of now, crystal is not supporting groups hierarchy (groups belonging to other groups).
At the moment, crystal doesn’t support multi-language environments.
Among the restrictions to be considered when publishing topics, pay attention to the fact that it is not possible to edit a topic without unpublishing it first and deleting a topic that is in the statuses of publishing, unpublishing or published.
In the articulated process of topic configuration, there are some limitations to take into account.
It is not possible to select a “number” column in the group by field for a table without binning, even if the number is an integer.
It is not possible to use different aggregations or column types on a single visualization where multiple sets of data are represented (e.g. multi-line chart).
For configuring over time objective visualizations, it is required to have one time column. Though you cannot have more than one.
You can only use time columns in tables, light tables & over time objective visualizations.
The limitations related to dynamic filters are:
You can’t select more than one dynamic “date” filter.
You can’t set a required value without a default value.
You cannot have more than three mandatory filters (excluding the time filter).
Default time range
The default time range can only be related to year-to-date, the last year, the last months, or to another X number of days, weeks or years up until the present day. Note that it is not possible to select “today” as the default time range.
As for the join table process, bear in mind that it’s not possible to join objects from different data sources.
The supported aggregation functions are the following:
Donut & semi-circular gauge
It’s not possible to perform operations between different fields (es: column A + column B).
Edit a column type
Note that you can only edit the column type in the topic wizard.
We hope this article will help you to experience crystal at her best.
Do you want to know more about topic creation? Check out our Tutorials for admins section on Resources!
If you have any questions about crystal’s features, you have encountered a problem or you would like to share your feedback, contact us using this form.