Re: How to know if all insertions are finished

On Fri, Mar 8, 2024 at 4:01 AM intmail01 <intmail01(at)gmail(dot)com> wrote:

> Hi,
>
> Is there any way to know if several insertion are terminated.
> I use libreoffice base to import at the same time many lines. When all
> lines are inserted I have to do some data check. I dont find any way to
> know if the insertion ends to start some function automatically.
> I tried to use a STATEMENT trigger type but all lines are treated as
> statement.
>

I think you are saying in your last line that each insert line is treated
as an individual statement, so you get a bunch of trigger notifications
instead of just one, and you don't know how to detect when you have
received the final insert?

The first thing I'd look for is whether I could wrap all the libreoffice
inserts into a single transaction block, and then event off of the
transaction block completing.

Barring that, and noting I'm not familiar with how libreoffice would send
the inserts, one option could be to put a listen/notify pattern at the end
of your insert code, if it's possible to add a line of sql at the end of
the inserts? Of course, if you can do that, you might also be able to wrap
the whole thing with a transaction, but listen/notify might be simpler to
event off of..

-- In session/connection 1
BEGIN;
-- Perform your bulk insert operation here
COMMIT;
NOTIFY inserts_done;

-- In session/connection 2
LISTEN inserts_done;
-- Once notification is received, proceed with necessary operations

If you can't do something like this, the only other (relatively horrible)
things I can think of would be to:

1. Put a dummy row at the end of your insert data (if you can guarantee
it would be inserted last during the bulk operation), and then build a
trigger/condition to detect insertion of a row matching the dummy data that
deletes the dummy row and then proceeds to kick off whatever other
processes you want, or:
2. Use a time based model, where you build an understanding of how long
your inserts take to execute, and build a monitor that kicks off on each
insert, and if another insert is not detected within a certain amount of
wait time, you conclude that there are no more inserts coming, and you then
kick off whatever other processes you want..

Hopefully someone with deeper Postgres knowledge has other, more reliable
solutions that leverage Postgres, but if your inserts are all discrete, and
you don't have control over the sql itself.

Steve