About
Do you have data that you need to access in a report from an additional data table, but joining them may make the tables too large? The JMP Virtual Join feature enables the main data table to access data from auxiliary data tables without physically joining the tables. Virtually joining tables saves memory, because the same data is not replicated in every table that references them.
Narration Script
Virtual Join links a main data table to one or more auxiliary data tables.
This feature enables the main data table to access data from the auxiliary data tables without physically joining the tables.
Virtually joining tables saves memory, because the same data is not replicated in every table that references them.
Let’s say we’re an automotive part supplier and maintain a very large data table with a column of Part Numbers, Dates and Sales figures and a second smaller table that also has Parts Numbers but in addition has the unique Part names.
We want to view the Part names in our reports. And since each table has a Part Number column we can use that Column as the Link ID.
Linking these will let us utilize all of our data together in a report even though it’s not in the same table.
And you can link multiple tables to the main table .
To demo this in JMP let’s look at Marketing Study Pizza experiment; this data is available inside of JMP for you to try Virtual Join yourself.
Suppose that respondents in a Marketing pizza experiment chose their favorite crust, topping, and cheese.
The team needs to view which cheese the respondents preferred. However the Cheese classifications are not in your main data table.
I’ll open the data from Help then the Sample Data Library and open Pizza Profiles and Pizza Responses.
We need to have all of the data tables open in JMP to Virtually Join them.
First, right-click the ID column in Pizza Profiles and select Link ID.
A data table can have only one Link ID column property. The Link ID column cannot have duplicate values.
This column contains unique values that correspond to values in Pizza Responses.
In Pizza Responses, select the three columns that begin with “Choice”.
Right-click and select Link Reference then Pizza Profiles.
A data table can have multiple referencing columns. The columns can reference different or the same data tables.
The selected columns are linked to the ID column in Pizza Profiles Data and appear in the main data table’s Columns list
Form the Pizza Responses data table, select Analyze then Distribution.
Scroll down to select the three Cheese columns in the referenced column groups, click Y, Columns, and click OK.
In this Distribution Report we can view Cheese classifications because they are virtually in our Data Table.
To share the data with another user, you might want to merge the data so that the data tables are permanently joined.
To merge the joined columns into the table that has a link reference, select Merge Referenced Data from the red triangle menu in the data table’s left pane.
The data is replicated from the referenced data table to the main data table. When you save the data table, the actual data is also saved.
Now try if for yourself with Movie Customers and Movie Inventory Sample Data in JMP and virtually join them for practice.
Thanks for watching and check the tutorial link below for more on Virtual Join.
