On 20.02.21 21:08, Andres Freund wrote:
It's not free though
Agreed. It's an additional call to a callback. Do you think that's
acceptable if limited to two-phase transactions only?
I'm wondering the opposite: What's a potential use case for handing
"trivially empty" transactions to the output plugin that's worth
incurring some cost for everyone?
Outlined in my previous mail: prepare the transaction on one node,
commit it on another one. The PREPARE of a transaction is an event a
user may well want to have replicated, without having to worry about
whether or not the transaction happens to be empty.
[ Imagine: ERROR: transaction cannot be replicated because it's empty.
HINT: add a dummy UPDATE so that Postgres always has
something to replicate, whatever else your app does
or does not do in the transaction. ]
Regards
Markus
