Wed, 2020-09-09 16:00
Hi all,
here is the situation :
- Create a filter A
- Create a filter B
- Create a filter C by merging filter A and B
- Modify filter A : for example add some symbols and relationships, remove some others
The question is : how to update C so that it reflects changes made in A ?
- Option 1 would be to manually apply the same modifications to C that were made to A. Not allways feasible if modifications to A are not documented.
- Option 2 would be to merge the new A with B and get a new and updated C. The trouble is we may have modified C itself inbetween ....
- Option 3 : what happens if we merge again C with itself and the new A ? Do we get the desired result, i.e. : new A filter definitions + B definitions + modifications made to C after the initial merge ?
Thanks !
Note : this is similar to that question dating from 2009
Hello Michel,
two things to consider here: The merge operation of two filters will produce a filter that contains the union set of 2 filters. So you cannot do modifications like removing elements from A and merging the removal on C. Likewise if you remove anything from C that originated from A in the merge, merging A onto C again will re-add it.
Also remember that every filter has got an identity, a GUID. So merging two versions of the filter "C" is not possible. They cannot exist in the same tenant at the same time. You first have to "duplicate" the filter C (producing a filter "D" with a new identity). Then you could modifiy either of them and use them in a merge operation. Also observe that just changing a filter's name does not change its identity.
Since the only filter operation is "merge", the only feasible strategy is to maintain partial filters and merge them to a productive filter. You should not modify the productive filter, if you want to generate it from partial filters. If you want to know the delta between two filters there is a report, which you can start on a selection of two filters: "Filter comparison report". It will produce an Excel file with only the differences, if you want.
So, to answer your initial question: Open Filter C. On step 2 of the wizard select "Merge filters" and select filters A and B. If you modified C in between, first create a new filter D from a merge of A and B. Then do a filter comparison between C and D, decide which changes are those of C and not those of A. Redo those changes in either A or B, so you can create C again cleanly from A and B. If you want, do a test merge F and compare it to your desired result C. Anyway try to return to having consistent base filters.
Thanks Michael
I guess we got a bit lazy and ended making modifications to the merged filter instead of making them to the base filter and then redoing the merge. Quicker but not sustainable in the long run.