On 7/19/23 17:15, David Rowley wrote:
> On Wed, 19 Jul 2023 at 07:41, Rob Sargent<robjsargent(at)gmail(dot)com> wrote:
>> You might consider deleting portions of the table in separate (consecutive) batches (maybe 5% per delete). And then truncate table is not logged so that might be an alternative.
> Can you explain why this would be a useful thing to do?
>
> It sounds to me like it would just create a load of needless WAL from
> the deletes and the vacuum that cleans up the dead rows each of which
> is more likely to cause lag problems on the replica servers, which the
> OP is trying to avoid.
>
> David
No, you're right. I was remembering problems with _deleting_
essentially all of a large table (with limited resources). The drop
might not have the same problem. But aren't they logged/transactional
and then in the WALs anyway.