Linking in a worksheet allows you to perform various actions on a table and then link the results into an existing table or worksheet.
What if you wanted to modify the Product Master table and link those results into the Sales Item Detail table? You might do this because you only want to link in additional information for a subset of the data. For example, in this tutorial you only want to link in the additional product information for items in the snacks department. You can accomplish this in the 1010data Insights Platform Trillion-Row Spreadsheet (TRS) by selecting the rows corresponding to that department in the Product Master table and then using the Link operation to add the data to the Sales Item Detail table. In this example, you are working with only 35 rows of data. However, for tables with billions of rows, linking in only the additional information you need is more efficient and can result in quicker processing.
To link in a worksheet:
Because the original Product Master table has been modified by the row selection, it is now considered a worksheet. The worksheet has four rows.
This worksheet can now be linked into your Sales Item Detail table in its current form.
Just like when you linked in the original Product Master table in Link in a table, link once more on the SKU columns.
The result is a new worksheet that has information from the Product Master worksheet only for those item SKUs that fall under department 22. However, the other rows in the Sales Item Detail table remain, and the columns from the Product Master worksheet are left blank for items not in department 22. This is useful if you want to look at additional information about one subset of rows in a table or worksheet but still maintain the original level of detail for the other rows.
As an alternative, what if you want to simply eliminate the rows in the Sales Item Detail table that are not applicable to the selection in the foreign worksheet (Product Master)? In that situation, you only need to change one setting. The beauty of the analysis timeline is that you can make that change very easily to obtain those results.
The process to link and select rows is nearly identical to the process of simply linking to another table or worksheet. The only difference is the results produced. Instead of applying the information from the foreign worksheet to the entire base table or worksheet, the Include matching rows linking option retains only those rows in the base table that correspond to the selection in the foreign table.
For instance, what if in the exercise you just completed above, you only wanted to see SKUs in the base worksheet that are in department 22? Since department information does not exist in the base table, you cannot make that selection. You could first link in the Product Master as the foreign table and then perform a row selection. However, that requires first linking in more rows than you need, which is less efficient. The best solution is to first select the rows in the Product Master table, then perform a link and select to eliminate the rows in the base table that cannot be linked.
With this in mind, go back and edit the link operation in the timeline to perform a link and select.
The result is a new worksheet with only the rows from the Sales Item Detail table that have SKUs in department 22, reflecting the selection from the Product Master worksheet. Only rows left in the Sales Item Detail worksheet are those that apply to the initial selection you made in the Product Master worksheet. This method allows you to use links more efficiently and effectively in your analyses.
The linking tutorials are intended to introduce you to the topic of linking, but it is a complex topic with many variations, which makes it very powerful. Finding ways to combine data sets and provide them with context is what the Insights Platform is all about. After reviewing these tutorials, take some time to explore tables and see if they have places where they can be joined by columns with similar information. This will help you understand how your data is interrelated, and start you down the path of deeper, more insightful analysis.