- New versions are created for all rows, even if the data is identical. > This quickly fills up the WAL and puts unnecessary load on the tablespace > drives. > > - If the conflict target is not the serial column, the sequence backing > the serial column gets incremented for every row. This quickly reaches the > point where the serial for new rows exceeds the range of an integer. > > >
It sounds like you aren't adding a WHERE clause to prevent the duplicate rows from being updated. It would help if you could share your query, but in general this could look like this: INSERT INTO my_table (col1, col2) SELECT col1, col2 FROM other_table ON CONFLICT (col1, col2) DO UPDATE SET (col1, col2) = (EXCLUDED.col1, EXCLUDED.col2) WHERE (my_table.col1, my_table.col2) IS DISTINCT FROM (EXCLUDED.col1, EXCLUDED.col2);
