It returns the TM1 username (or Windows domain username depending on the security system being used – for example, “GER\JEREMY”) of the user who runs the query. Note that you may need to give all users Read access to the }Clients dimension and all its elements.

One of the special features of using MDX with TM1 dimensions is that existing subsets can be used within the query for defining a new subset. This can be useful in allowing a simpler ‘building block’ approach and for not having to repeat the same code over and over again – and having to maintain it.

Used throughout this section, [Report Date] is an existing subset in the Date dimension containing one leaf date member and [test2] is an existing 20-member subset.

ToggleDrillState changes the default drill state from a returned set – so if the first query returns a member in a hierarchy rolled up then it will drill it down, or vice versa.

For example,
{[Product].[Customer Lending].Children}
Returns:

The function takes two sets as its mandatory parameters and removes those members in the first set that also exist in the second. In other words it returns only those members that are not in common between the two sets, but note that members that are unique to the second set are not included in the result set.

Intersect returns only members that appear in both of two sets. One example might be to show products that performed well both last year and this year, or customers that are both high volume and high margin. The default is to drop duplicates although “, ALL” can be added if these are required.

Union joins two sets together, returning the members of each set, optionally retaining or dropping duplicates (default is to drop).

This creates a single list of the top 5 and worst 5 products.
{UNION(
TOPCOUNT( {TM1FILTERBYLEVEL( {TM1SUBSETALL( [Product] )}, 0)}, 5, [Test].([Posting Measures].[Amount]) ),
BOTTOMCOUNT( {TM1FILTERBYLEVEL( {TM1SUBSETALL( [Product] )}, 0)}, 5, [Test].([Posting Measures].[Amount]) )
)}

Where TopCount and BottomCount sort the values automatically and chop the list to leave only the most extreme values, Head combined with Filter works in a similar manner but Head then returns the FIRST members of the filtered set in their original dimension order.

These queries simply return the first and last members of the Product dimension as listed when you hit the ‘All’ button:
{Head ( TM1SubsetAll ( [Product] ) )}
{Tail ( TM1SubsetAll ( [Product] ) )}

This returns members that match a certain attribute value using the Filter function.
{FILTER( {TM1SUBSETALL( [Product] )}, [Product].[Category] = "Customer Lending")}

This example returns the members that have an Amount value in the Test cube above 18. The [Product].CurrentMember part is optional here but it makes the next example clearer.
{FILTER( {TM1FILTERBYLEVEL( {TM1SUBSETALL( [Product] )}, 0)},
[Test].([Product].CurrentMember, [Posting Measures].[Amount]) > 18 )}

Lags and Leads are the equivalent of Dnext/Dprev.
{ [Date].[2006-10-03].Lead(1) }
will return 2006-10-04.

Lead(n) is the same as Lag(-n) so either function can be used in place of the other by using a negative value, but if only one direction will ever be needed in a given situation then you should use the correct one for understandability’s sake. Note that they only return a single member so to return the set of members between two members you can use the lastperiods function.