Question

I have a table that gets updated from an outside source. It normally sits empty until they push data to me. With this data I am supposed to add, update or delete records in two other tables (link by a primary/foreign key). Data is pushed to me one row at a time and occasionally in a large download twice a year. They want me to update my tables in real time. SHould I use a trigger and have it read line by line or merge the tables?

Answer 1

I’d have a scheduled job that runs a sproc to check for work to do in that table, and them process them in batches. Have a column on the import/staging table that you can update with a batch number or timestamp so if something goes wrong (like they have pushed you some goofy data) you know where to restart from and can identify which row caused the problem.

If you use a trigger, not only might it slow down them feeding you a large batch of data, but you’ll also possibly lose the ability to keep a record of where the process got to if it fails.

If it was always one row at a time then I think the trigger method would be okay option.

Edit: Just to clarify the point about batch number/timestamp, this is so if you have new/unexpected data which crashes your import, you can alter the code and re-run the process as much as you like without having to ask for a fresh import.