Nested CDTs vs Non Nested CDTs

I Think it's better to approach moving forward without Nested CDT. Nexted CDT makes more difficult when we are doing the reporting. Especially When we are doing the aggregation and Adding Different filter conditions to the rule I recommend not to create them but if you really wanna try that you end up creating the database view and creating the Extra CDT for it. I would recommend just create the Database tables and then Create the CDT from the Datastore.Reduce the complexity to the CDT is much preferable.
Hope this helps.

Thank you!
Rajesh Kilaru

Hello Jerry

i recommend you to take a look this thread.
community.appian.com/.../58772

Jose

HI jerrys,
As far as I know, nested CDTs are not recommended due to several issues like performance degradation , conversion of data becomes difficult and also debugging the process model and accessing the unnecessary data becomes cumbersome.So in order to avoid this you can use plain CDT.
Refer the link below for more info:
community.appian.com/.../database-performance-best-practices.


Thanks,
ravalik

Hi Jerry,

In addition to other comments, Avoid using nested CDT's until it is badly required. I just wanted to share my work experience. In all of the applications that I have worked on is maintain simple CDT's and the relationships maintained with just to point the foreign key constraints in the chain table. It is always better to go with create a DB object and then create CDT out of it.

But few people may take the other approach like, creating the CDT and then create DB objects out of it. Most probably this approach might be used when you develop pretty new application from scratch. But we use to use this approach when we want to create some kind of POC applications which can be showcased to customers.

Hi Jerry,

As others mentioned, while creating Nested CDT's, we need to check the below mentioned points:

(1) What is the functionality? Can we avoid by proceeding with two or more tables referenced to each other? If not, can we create a complex view having the complete data. I prefer the Complex View. A CDT can be created mapping the complex view can be used in creation of Form(while Storing data), Summary Dashboards (while retrieving data), Records, Reports etc. This is simple and also effects the Performance.

(2) If creating complex View is not feasible, Nested CDT approach can be used. But recommended Best Practice is to have it only for one level.

Thanks,
Farnaz

Hi,
As per Appian, if there is no other way, they suggest to go ahead with 1 level of nested CDT and nested CDT's are not a best practice and below are some points:
1. We need to invest time in extra amount of coding due to nested CDTS's and also it will be a challenging task during process instance debugging.
2. In some instances, we wish you fetch only data from parent table, in such case data from child table will also be fetched due to one-many relationships. Also, during data conversions, from JSON and vice versa, the complexity will be increased.
3. Though in above scenarios there will not be a necessity of view creation but unnecessary complexity is increased. Hence, the best way is to go with normal CDT and create views accordingly which will accelerate the performance as well.

Thanks.

Thank you all for your input