Great idea ! This brought the time per INSERT into the parent table down
to a consistent ~0.065ms again (compared to 0.05ms when completely
removing the trigger, so penalty for the trigger is roughly ~20%).
> On Sat, 17 Jul 2021 at 16:40, Justin Pryzby <pryzby@telsasoft.com> wrote:
>> You could run a single UPDATE rather than 30k triggers.
>> Or switch to an INSERT on the table, with an index on it, and call
>> max(last_parent_table_change) from whatever needs to ingest it. And prune the
>> old entries and vacuum it outside the transaction. Maybe someone else will
>> have a better suggestion.
> Maybe just change the UPDATE statement to:
>
> UPDATE data_sync SET last_parent_table_change=CURRENT_TIMESTAMP WHERE
> last_parent_table_change <> CURRENT_TIMESTAMP;
>
> That should reduce the number of actual updates to 1 per transaction.
>
> David
