Crosstabs limits and constraints
This section provides an overview of the limits that need to be considered when working with crosstabs in Engine.
Y Axis
The maximum theoretical number of discrete values in a Y axis column is 2 billion. However, in practice this is dependent on the amount of memory that is required to run the Crosstab (see Memory Requirements for Crosstabs).
X Axis
The maximum theoretical number of discrete values in a X axis column is 512. However, in practice this is dependent on the amount of memory that is required to run the Crosstab (see Memory Requirements for Crosstabs)
Multi-Dimensional Axes
The theoretical maximum number of Y Axes that can be added to a multi-dimensional Crosstab is 19. However, the limit may also be determined by the amount of memory required to calculate the Crosstab. This is dependent on the memory available to the system.
There is an upper limit of 2 billion discrete values for the combined Y axes - that is the product of the number of discrete values in each column.
It is possible to add multiple X Axes to a Crosstab - however, the number of discrete values must not exceed 512.
It is not possible to specify an array field or parametric field as an axis in a multi-dimensional Crosstab.
Valid Axis Column Types
| Column Type | Used as Axis? | Comment |
|---|---|---|
| Field (raw data) | YES | Must be indexed |
| Decodes | YES | |
| Array Fields | YES |
Cannot be inverted Cannot be used in multi-dimensional Crosstabs. |
| Expressions | YES | |
| Numeric Bands | YES | |
| Quantile Bands | YES | |
| Parametric Remaps | YES | Parametric remaps cannot be used in multi-dimensional crosstabs.
Correction - Previous versions of the documentation stated that only one parametric Remap could be added to a multi-dimensional Crosstab. |
| Domains | YES | Only permanent domains can be added as an axis |
Base Filter
Only one base filter may be applied to a Crosstab. The owner table of the domain must be linked to the Crosstab. There are no limits on the data structure between the owner table of the base filter and the resolution table of the Crosstab.
Target Filter
The maximum number of filters that can be added to crosstab via the ICrosstab.SetAxis property is 32.
Each filter that is added to the crosstab will generate a sheet of results.
Resolution Rules for Axes
The Y Axis table must be linked to the resolution table of the Crosstab.
If present, the X Axis table must be linked to the resolution table of the Crosstab.
The maximum number of links that can be traversed in a Crosstab is 2.
Array Fields
It is not possible to select an array field as an axis or filter if it comes from the MANY side of a link with the resolution table of the Crosstab.
Function Crosstabs
For all functions other than COUNT, it is not possible to specify a function column that comes from the MANY side of a ONE to MANY link.
Data Types
The following summarizes which data types are valid for use in Function crosstabs:
| Function | Valid Data Types |
|---|---|
| SUM | INTEGER, REAL |
| MEAN | INTEGER, REAL |
| MIN | INTEGER, REAL, DATE, DATETIME, TIME |
| MAX | INTEGER, REAL, DATE, DATETIME, TIME |
| STDDEV | INTEGER, REAL |
Axis Filters
As long as both the Axis table and the Filter table are linked to the resolution table of the Crosstab there are no resolution limits when setting axis filters.
A filter can be set on any X or Y axis that is applied.
Axis filters can be applied to none, one or many of the crosstab axes.
