It is a Feature in Web Intelligence which links the data from two data providers or two queries so that we can use them in one block and compare the information between the queries more accurately.
It is the ability to combine data coming from more than one data source into one document. This is done by creating multiple data providers, linking them up by using a common dimension and using the combine results in a report block. Like when 2 database tables are linked in a universe certain columns are used to join them together. Dimensions serve this role in linking 2 data providers.
Merge Dimensions allow you to build reports from multiple data sources.
If you want to show information from 2 data providers in a single report block then we use MDs.
If you have queries from the same universe that include the exact same dimension objects, those will be automatically merged. Let’s say an object “address” is there in a class ”vendor” and you have another object “address” in a class “customer”. These 2 objects have the same name and are from the same universe. Will they merge? NO.
Rules for Merging Dimensions
Example:
Query1:
EMP_ID EMP_Name Salary
Query2:
CUST ID CUST Name Revenue
Now, if you try to use all these objects in the same block you will get #Data sync Error. As Web I will not able to find any relation between these Queries.
Now Merge EMP ID and CUST ID
Merge Query:
Merge ID Revenue Salary
Now, this will Work as Full Outer Join. If I involve any one Non Merged Dimension in this Merge Query Block the results will show dimension values pertaining to that Query only.
Example:
Merge ID EMP Name Revenue Salary
Merge ID CUST Name Revenue Salary
So, basically it is working as Left or Right Outer Join when we try to use any non-merged dimension in the merged block.
(OR)
Similarly, If you don’t use Merge ID column and use EMP ID or CUST ID along with measures Revenue and Salary that will also work as left/right outer join.
Extend Merged Dimensions: If we want to make the functionality of a left or right outer join to work as full outer join then we should enable “Extend Merged Dimensions”. Note: This works only when unmerged dimension is not selected in the block. OR If you want to see full outer join results on left/right query, we use Extend Merged Dimensions.
It is the ability to combine data coming from more than one data source into one document. This is done by creating multiple data providers, linking them up by using a common dimension and using the combine results in a report block. Like when 2 database tables are linked in a universe certain columns are used to join them together. Dimensions serve this role in linking 2 data providers.
Merge Dimensions allow you to build reports from multiple data sources.
If you want to show information from 2 data providers in a single report block then we use MDs.
If you have queries from the same universe that include the exact same dimension objects, those will be automatically merged. Let’s say an object “address” is there in a class ”vendor” and you have another object “address” in a class “customer”. These 2 objects have the same name and are from the same universe. Will they merge? NO.
Rules for Merging Dimensions
- For Merging dimensions there should be at least one common dimension.
- The dimension objects do not have to have the same name.
- You can link only dimension objects.
- The merged dimension object must have a common data type.
- Object Value must be in same case.
- Format of values must be same.
Example:
Query1:
EMP_ID EMP_Name Salary
Query2:
CUST ID CUST Name Revenue
Now, if you try to use all these objects in the same block you will get #Data sync Error. As Web I will not able to find any relation between these Queries.
Now Merge EMP ID and CUST ID
Merge Query:
Merge ID Revenue Salary
Now, this will Work as Full Outer Join. If I involve any one Non Merged Dimension in this Merge Query Block the results will show dimension values pertaining to that Query only.
Example:
Merge ID EMP Name Revenue Salary
Merge ID CUST Name Revenue Salary
So, basically it is working as Left or Right Outer Join when we try to use any non-merged dimension in the merged block.
(OR)
Similarly, If you don’t use Merge ID column and use EMP ID or CUST ID along with measures Revenue and Salary that will also work as left/right outer join.
Extend Merged Dimensions: If we want to make the functionality of a left or right outer join to work as full outer join then we should enable “Extend Merged Dimensions”. Note: This works only when unmerged dimension is not selected in the block. OR If you want to see full outer join results on left/right query, we use Extend Merged Dimensions.