[andorov]

worth re-upping -

postgres requests an id from the sequence for each row of the incoming data ahead of time since it doesn't know which rows are updates and which are inserts (although presumably this could be changed?). the sequence doesn't reset down for the unused so this can eat through it unexpectedly quickly if you have a table with a relatively large volume of updates.

also as a tip if you hit the max integer for the sequence and need space to implement a fundamental fix you can quickly change the sequence to start at -1 and go down. there's no issue with negative ids since they're also integers.

[anarazel]

> postgres requests an id from the sequence for each row of the incoming data ahead of time since it doesn't know which rows are updates and which are inserts (although presumably this could be changed?).

Not in any sort of general way - the sequence can be part of the unique key that you're conflicting on.