Slicing & Dicing
The term "slice & dice" became popular when multidimensional databases became a thing. These new (st the time) database systems allowed base data to be seen from various perspectives (dimensions) and summarized, or aggregated, in various ways at multiple levels, so the term "slice & dice" became handy in referring to what a database user does in order to make sense or use of a set of data that may initially seem impervious.
But slicing & dicing is not limited to such database systems. A Memento user may collect data of various sorts, linked together in various ways, and it can be hard to see truly useful views of that data that are effective in making decisions. We call the attempt to do so slicing & dicing, and Memento provides several good tools to enable it.
The following sections provide an overview to the process of slicing & dicing. If you already know what you want to do and want to see specifically how to do it in Memento, see How:Slice & Dice Library Data.
Preparing for maximal slicing & dicing benefit
To prepare for subsequent analysis of the data, add related data and calculations to the data and then define aggregations of the data.
- Calculate within the entry
- First, enrich each entry as much as possible with information derived from data entered into the entry. In an entry for an order line item, calculate the total from the quantity and unit price. In an entry for a new tank of gasoline, calculate the cost of a tank of gasoline from the number of gallons and cost per gallon, and calculate the cost per mile from the cost of the tank and the elapsed mileage.
- Calculate with related data
- Then, reach into related libraries to include data or calculate with data that would be useful during ad hoc slicing & dicing.
- Aggregation
- Calculate useful information — such as totals, averages, maximums, and minimums — across all entries in the library. During slicing & dicing, these calculations can become subtotals and other calculations for subsets of library entries.
Slicing & Dicing
Once the libraries are set up, and data is entered, the job of viewing the data and making sense of it is at hand. While viewing the list of library entries, the following activities will give you the best possible look at the data and any wisdom that may be contained within it.
- Filtering
- First, you can restrict your investigation to a portion of the entries in the library. For example, you can filter to view orders only for a particular customer or gasoline only for your current car.
- Grouping
- Then, within the filtered data, you may want to see certain data sparsely from others, such as orders of certain products or fuel purchases from certain gas stations. If you group your order entries by product or your fuel purchase entries by gas station, you can then not only see them separately and quickly switch between them, but aggregations will be displayed for each, in addition to aggregation of the entire set.
- Sorting
- With sorting, you can determine the order of entries, and if grouped, the order of the groups and the order of entries within groups.
- Putting it all together
- It is not always clear how clarity and wisdom unfolds from within the data, but with artful use of these functions, one can often detect patterns in the data that would otherwise not be apparent. Use sorting carefully to enhance the effect of grouping. Grouping can often be used in place of filtering.