Re: question regarding copyData containers

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Jerome Wagner <jerome(dot)wagner(at)laposte(dot)net>
Cc: pgsql-hackers(at)lists(dot)postgresql(dot)org
Subject: Re: question regarding copyData containers
Date: 2020-06-03 18:25:07
Message-ID: 1141986.1591208707@sss.pgh.pa.us
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

Jerome Wagner <jerome(dot)wagner(at)laposte(dot)net> writes:
> now my question is the following :
> is it ok to consider that over the long term copyData is simply a transport
> container that exists only to allow the multiplexing of events in the
> protocol but that messages inside could be chunked over several copyData
> events ?

Yes, the expectation is that clients can send CopyData messages that are
split up however they choose; the message boundaries needn't correspond
to any semantic boundaries in the data stream.

The rule in the other direction, that a message corresponds to one table
row, is something that might not last forever either. As we get more
people working with large data values, there's going to be pressure to
set some smaller limit on message size.

regards, tom lane

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Tom Lane 2020-06-03 18:35:29 Re: elog(DEBUG2 in SpinLocked section.
Previous Message Tom Lane 2020-06-03 18:19:45 Atomic operations within spinlocks