Matthew Phillips schrieb am 19.12.2019 um 00:12: > Hi, With the current READ UNCOMMITTED discussion happening on > pgsql-hackers [1], It did raise a question/use-case I recently > encountered and could not find a satisfactory solution for. If > someone is attempting to poll for new records on a high insert volume > table that has a monotonically increasing id, what is the best way to > do it? As is, with a nave implementation, rows are not guaranteed to > appear in monotonic order; so if you were to keep a $MAX_ID, and > SELECT WHERE p_id > $MAX_ID, you would hit gaps. Is there a clean way > to do this? I've seen READ UNCOMMITTED used for this with DB2.
In my understanding READ UNCOMMITTED in other databases is typically used to avoid read-locks which Postgres doesn't have. So I wonder what benefits READ UNCOMMITTED would have to begin with. But, if you want to poll for new rows, then why don't you use a timestamp column? select * from the_table where created_at >= <last check time>
