Canceling form with related table changed

[uniglass]

Hi
Lets say we have invoice form (table_1) and we changed and saved something in related table_2. Now we want to cancel invoice form and roll back all the changes in related table_2.
What is your idea for handling this cancel? We use temporary tables for related records and update table_2 only when request is completed. Other ideas ?

 

[ShankarJ]

Hi!

If the update is done inside a transaction frame, you can roll back the updates. Check out LOGOUT, COMMIT & ROLLBACK in the help.

Regards

 

[uniglass]

We use transactions when possible but in this situation it doesn't work.
User's edit form can lock related table for long time. We have other automated processes writing into that tables that won't stop and wait for COMMIT OR ROLLBACK ( scanners reading barcodes)

We tried different isolation levels but SQL manual clarified all.

PostgreSQL Documentation
Chapter 12. Concurrency Control

...
This means it is a bad idea for applications to hold transactions open for long periods of time (e.g., while waiting for user input).