Filtering, Sorting and Ranking

Transcription

1 Filtering, Sorting and Ranking Content: THE PRINCIPLES FILTERING/RANKING/SORTING... 2 EXAMPLE... 3 Step 1: Simple Filtering... 3 Step 2: Sorting on a different dimension... 5 Step 3: Combining Ranking, Filtering and Sorting... 6

2 The principles Filtering/Ranking/Sorting Analysis Services provides powerful filtering and ranking capabilities in its multidimensional language MDX that are conceptually simple once the basic principles are understood. Most IS people come to OLAP from the relational world and are used to the concept of the WHERE and ORDER Clause in SQL operating conceptually on the result set. In MDX the way that we conceptualise the process is different in that the filter/ranking and sorting operate on the axes to return the dimension members of that axes and then the data cell populate as a second step. This is extremely powerful as in essence the grid layout in the axes can have differing filters/rankings for each axes i.e Show me the sales for 1997 based on 1998 sales being over a certain limit for Products that sold less than 1000 units in the first quarter of Expand that out into a separate filter or rank for each axes which can reference any member set of multiple dimensions and the analysis capabilities to slice and dice the data are endless. XLCubed offers the capability to take advantage of this capability and this represents a couple of user interface challenges such that during normal usage the end user is not confronted with too much complexity. XLCubed therefore provides an advanced and basic mode in its filtering/ranking/sorting dialogs to allow the selection of specific members. In basic mode operations happen at the default level of all dimensions. In the current version this means that when common dimensional filters are used across all axes they need to be specified in each axes and filters and in future versions this may be addressed. When it comes to filtering and ranking within an axe(s), different filters and rankings can be combined and XLCubed provides the ability to have multiple filters that can be combined in a number of manners. The default is merge i.e the result of the first filter is fed into the next but other set operators are supported (UNION, INTERSECT, EXCLUDE, SUBTRACT) Feedback from customers is that this makes advanced analysis possible but like any powerful concept it needs to be understood. One very common and simple utilisation is UNION which is useful for doing a top and bottom in the same grid i.e Show me the top 10 and worst 10 salesman and products in the last period XLCubed Limited page 2

3 Example The following tutorial shows how to filter, sort and rank using different members of a cube. Step 1: Simple Filtering Lets say I want to find the Products at brand name level that sold more than 50 units in Q1 and show the 1997 and Q1, Q2, Q3, Q4 Sales 1. Start by using the Quick Grid ( ) option on the sales cube (supplied with XLCubed), this will create the basic Grid. 2. Display the Member Selector dialogue by clicking on the Product label in the Grid 3. Drag the Brand Name level over to the right of the dialogue 4. Click the Filter icon ( ) to bring up the filter pane: 5. Click the filter icon ( ) on the filter pane (lower RHS of the dialogue) and select Q1 as the member for the Time dimension XLCubed Limited page 3

4 6. Click OK to select the member and then click Next> and enter 50 as the value in the Value to Compare Against field 7. Click Finish 8. Run the Report The Grid shows the report and you can also display the MDX that has been written using the RMB>Properties option: XLCubed Limited page 4

5 Step 2: Sorting on a different dimension Now we want to sort the report in descending order of the Q1 sales 1. Display the Member Selector dialogue for the Product dimension by clicking on the Product label in the Grid 2. Select the Sort tab in the Member Selector dialogue 3. Click the Sort by Measure radio button 4. Click the Advanced button 5. Select the Time dimension and select the Q1 member: 6. Click OK on the Member Selection dialogue 7. Choose Descending as the Order on the Sort tab 8. Click OK run the report the report runs and the MDX that is written is shown XLCubed Limited page 5

6 Step 3: Combining Ranking, Filtering and Sorting Now lets say we want to combine ranking with filtering to find the bottom 10 selling products at brand name level that have sold more than 50 units in Q1 1. Display the Product Member Selector dialogue (see previous steps) 2. Press the Ranking icon ( ) on the filter pane, this will display the Ranking dialogue 3. Select Bottom from the Include the dropdown and then enter 10 (default) in the items field: 4. Click the Advanced button and select the Time dimension and select Q1 5. Run the grid and the MDX is shown XLCubed Limited page 6