How to handle concurency and atomic DB actions

RE: How to handle concurency and atomic DB actions

cedric02 — Mon, 28 Mar 2022 07:12:58 GMT

Thank you Stefan, maybe I have to make some concurrency tests, to see how Appian deals with this kind of stored procedure.

RE: How to handle concurency and atomic DB actions

Stefan Helzle — Mon, 28 Mar 2022 07:00:15 GMT

Appian does not know about any concurrency in process models. I do not have any good ideas, but this seems like a problem to be solved inside the database.

RE: How to handle concurency and atomic DB actions

cedric02 — Mon, 28 Mar 2022 06:55:40 GMT

Yes I've verified, our Appian DB is set in AUTO COMMIT mode.

- If my stored Proc, does just this : SELECT Counter, UPDATE contract, UPDATE Counter,

I'm afraid that 2 different contracts may stored an identical "sequence_number".

- So I was thinking about using "SELECT FOR UPDATE" command to book the counter.

In that case, I wast asking me how would an Appian process would act ?

Does the concurrent process will wait for this resource (and retry?) ?

Does it would throw an error ?

RE: How to handle concurency and atomic DB actions

Stefan Helzle — Mon, 28 Mar 2022 06:43:50 GMT

When calling a stored procedure, I assume that Appian will not do any transaction control. This makes only sense for simple inserts and updates.

RE: How to handle concurency and atomic DB actions

cedric02 — Mon, 28 Mar 2022 06:41:29 GMT

Hi Stefan,
Yes it was the first solution I've suggested above (PL/SQL)

RE: How to handle concurency and atomic DB actions

Stefan Helzle — Sun, 27 Mar 2022 19:18:10 GMT

You have some interesting requirements here. Did you think about a stored procedure?