Merge Dimension
This is a feature in Web
Intelligence which allows linking of two data providers(or 2 queries).
Basically we merge objects
from two or more queries in one webi report, so that we can use them in same
block.
Mandatory condition to merge
objects is to have same data type.
For eg. See below tables , coming from two different
queries in webi report.
Query 1
Query 2
Now if you try to use all these objects in same block ,
you will get data sync error.(As webi will not be able to find any relation
between these queries)
I will now merge empid and cust id.
Merge Id is showing all rows coming from emp id and cust id
and their corresponding revenue and salary column values.
This is now showing results as Full outer join.
But if I involve any one non-merged dimension in this block,
the results will start showing dimension values pertaining to that query only.
So basically it is working as Left or Right Outer join when
we try to use any dimension in the block which is not merged.
But we will not be able to use both emp name and cust name
in same block as these are not merged.
We will get data sync error if we try to use them in same
block.
Similarly if you don’t use merge id column and use emp id or
cust id along with revenue and salary, that will work as Left or Right outer
join and not as Full outer join.
So this explains when merge dimension works as Full outer
join and when it works as left or Right outer join.
There is also one option which makes the functionality of
left or right outer join to work as full outer join. i.e. Extended merge
dimension. (note:- but this works only when unmerged dimension is not selected
in the block)
See for below example.
When I used cust id revenue and salary, the block look like
this:
So its showing data as left outer join .
Now I will check the option”Extended Merge Dimension” from
document properties.
Now it will work as full outer join as shown in screenshot:
So this option makes the query to
give full outer join result set even if you have selected specific and not merged
object in the block.
Note: this option wont work if
you use non-merged dimension in the
block. For eg. If you use cust name in the above block it wont work as full
outer join.
