About Transaction Management

RE: About Transaction Management

Prasanna — Wed, 16 Oct 2024 14:52:17 GMT

Hello,

I have a similar requirement and may I know what was the approach used to handle this requirement ?

Is Stored procedure is the best way to handle this or is there any better approach to do in Appian process itself ?

Thanks

RE: About Transaction Management

Stefan Helzle — Wed, 07 Jun 2023 10:59:14 GMT

Agreed. Tools have a specific purpose and should be used accordingly.

RE: About Transaction Management

Stewart Burchell — Wed, 07 Jun 2023 10:06:26 GMT

Understood and appreciate where you're coming from. We have to recognize the alternate danger of trying to do everything in Appian even when it doesn't meet the actual need as I feel this example highlights.

RE: About Transaction Management

Stefan Helzle — Wed, 07 Jun 2023 09:47:58 GMT

LOL. I appreciate that you disagree. And the pattern I described does not fit all scenarios.

I try to keep as much logic as possible inside Appian and only offload to external systems, which includes the database, only when I have to. Now, when people join the Appian universe from a more database focused environment, some try to stay with their old approaches and loose a lot from the simplicity of Appian.

RE: About Transaction Management

Stewart Burchell — Wed, 07 Jun 2023 08:19:30 GMT

docs.appian.com/.../Execute_Stored_Procedure_Smart_Service.html

RE: About Transaction Management

Stewart Burchell — Wed, 07 Jun 2023 08:17:43 GMT

Probably for the first time ever I have to disagree with you. Here's why;

Execute the Delete Smart Service - this works
Execute the Write Smart Service - this fails
(Now I have to design a rollback to write back to the DB the rows I just deleted.)
I execute the rollback thread - this also fails
Now I am (as we say here) in a complete muddle!

Until we get native "Begin Transaction" , "End Transaction", "Rollback Transaction" commands that can bracket multiple Smart Services in an Appian Process then by far the safest and reliable method is to use the DB's native functionality and incorporate this in a Stored Procedure.

RE: About Transaction Management

Meme02 — Wed, 07 Jun 2023 02:02:27 GMT

Thanks for the answer. I understand what you mean but in order to fulfill the request from the client we need to create many different tables to manage the data. I'm a little nervous when doing data write or delete in tables without transaction manager.

RE: About Transaction Management

Meme02 — Wed, 07 Jun 2023 01:56:29 GMT

Thanks for the answer. Is there any concrete example of how to use it on Appian. I didn't find much useful information on how to use it nor how to feed information from the process variable to it.

RE: About Transaction Management

Meme02 — Wed, 07 Jun 2023 01:51:45 GMT

My question is just one of the examples. We have multiple tables that need to be deleted or written at the same time. We've been thinking about Write to Multiple Data Store Entities but it seems to only allow writes, not deletes. So we have to separate delete and write in two. Then the deleete operation will not be recovered even if the later performed write operation fails. So I'm considering using Query DataBase to do both in one node. When one of the tasks in the node fails it returns an error and all the tasks in the node are not executed.

RE: About Transaction Management

Stefan Helzle — Tue, 06 Jun 2023 12:57:27 GMT

I my experience, it is a better approach to not make the database manage a transaction, but to look at the Appian process to be that instance.

RE: About Transaction Management

Stewart Burchell — Tue, 06 Jun 2023 11:38:23 GMT

Alternatively you can write a Stored Procedure that conducts both Write and Delete operations in the scope of a single transaction and then invoke that from Appian. You'd need to detect any failures/rollbacks issued from the Stored Procedure and handle this in your process model so that the appropriate notification(s) and action(s) can be conducted.

RE: About Transaction Management

Harshit Bumb (Appyzie) — Tue, 06 Jun 2023 09:39:11 GMT

Query Database smart service? Why you want to use that?

RE: About Transaction Management

Meme02 — Tue, 06 Jun 2023 07:52:24 GMT

Thank you for your reply. I'm thinking about query database, what about this？

RE: About Transaction Management

Harshit Bumb (Appyzie) — Tue, 06 Jun 2023 06:58:27 GMT

You have to use two different services for the same.
For your use-case, you can create a process where you always keep a backup of what was deleted and what was inserted so you can insert the deleted ones and delete the inserted ones if the process fails.