Features of Parsing Aggregation Expressions

Aggregation expressions are determined by the following properties:

Suppose that the time series database contains N identifying dimensions, and the aggregation filter has M of them set.

When the element is set, it is allowed to use N, N+1, N-M or N-M+1 parts in the expression:

On specifying N parts it is considered that the user specified all dimensions, and for this element the filter is not used. Example: {Albania|BCA} or {{Country}|BCA} (with parameter).
When N+1 parts is specified, it is considered that the user specified all dimensions + calendar level. For this element the filter is not used. Example: {Albania|BCA|Q}.
When N-M parts are specified, it is considered that the user specified only the dimensions, which are not in the filter. Example: {BCA}, filter contains Country dimension.
When N-M+1 parts are specified, it is considered that the user specified only the dimensions, which are not in the filter + calendar level. Example: {BCA|Q}, filter contains Country dimension.
If M=1, and N parts are specified in the element, the attempt of "a" variant analysis is made. If it is unsuccessful, the attempt of "d" variant analysis is made. There is a pitfall here: if the last specified dimension contains A, S, Q, M, W, D elements, it is impossible to specify calendar dimension because the analysis is executed using the "a" variant.
In other cases an error occurs.

If N = M, the X symbol is used to set the element from the filter.

If the analysis is not used (the element selection is set manually) to set aggregation expression, use the following rules:

By dimensions, missing in the aggregation filter, the single selection must be set.
For the dimensions, which are in the filter:
- Empty selection is specified. On calculation the selection from the filter is used.
- The single selection is used. It is considered that the user specified all dimensions, and for this element the filter is not used.