# Limitations When Summarizing Measures in DMR Data Sources

There are limitations when summarizing dimensionally-modeled relational (DMR) measures
and semi-additive measures in crosstabs using the aggregation function

```
count
distinct
```

, `median`

, `standard-deviation`

, or
`variance`

.
The following limitations can produce empty or error cells when the report is run:

- The aggregation function must apply to all members of a level or all children of a member.
- To use OLAP functions in detail filters that are applied to a dimension that
is not in the report, or is at a level below what is being reported, only the functions
`children`

,`level`

,`members`

,`roleValue`

, and`rootMembers`

will work. - You cannot define detail filters that reference one or more measures and are set to After auto aggregation.
- You cannot define context filters that have more than one member from a dimension that does not appear in the report.
- Context filters that have more than one member from a dimension that appears in the report produce errors in all cells that are ancestors of the slicer members.
- If a crosstab has a row that is a set of members from one dimension (dimension A) and another row that is a set of members from another dimension (dimension B), and a context filter containing members from dimension A is defined, error cells are produced in the row that contains members from dimension B.
- If a context filter contains members from a dimension, and a crosstab has a row that is a set of members from a higher level than the slicer members, error cells are produced for that row.
- Error cells are produced when drilling down on a crosstab that has two nested levels.

If you do not consider these limitations in a calculation, the report may return inaccurate results.

If there is a non-measure calculation that returns a constant or contains a summary function, and the calculation has a lower solve order than the measure being aggregated, error cells are returned for the aggregated measure.

In list reports, error cells are produced as a result of these limitations if
the list uses an OLAP function other than `children`

, `filter`

,
`level`

, `members`

, `roleValue`

, and
`rootMembers`

.