Analysis Services Programming
Cumulative Effect of Transactions on Data
When multiple users are connected to a cube and their changes are in conflict, the last changes made are the ones that take effect. Updates recorded in the writeback table of a cube are cumulative, so the cube is displayed with the net effect of all changes in the writeback table. The last user to commit an update to a cell determines the displayed values of the cell and all precalculated cells that are derived from it.
The act of updating cells is performed atomically for each cube. That is, each committed update is recorded separately in the writeback table.