Re: COPY FROM WHEN condition

Hi,

On 2019-04-04 12:04:28 -0700, Andres Freund wrote:
> On 2019-04-03 22:20:00 -0700, Andres Freund wrote:
> > On 2019-04-03 20:00:09 +1300, David Rowley wrote:
> > > Oops, I forgot about that one. v4 attached.
> > 
> > I'm pretty happy with this. I'm doing some minor changes (e.g. don't
> > like the function comment formatting that much, the tableam callback
> > needs docs, stuff like that), and then I'm going to push it tomorrow.
> 
> After another read, I also think I'm going to rename the functions a
> bit. CopyMultiInsertInfo_SetupBuffer, with its mix of camel-case and
> underscores, just doesn't seem to mix well with copy.c and also just
> generally other postgres code. I feel we already have too many different
> naming conventions...

I've pushed this now. Besides those naming changes, I'd to re-add the
zero initialization (I did end up seing compiler warnings when compiling
with optimizations).  Also some comment fixes.

I added one more flush location, when inserting into a partition that
cannot use batching - there might e.g. be triggers looking at rows in
other partitions or such.

I found some pretty minor slowdown for COPYing narrow rows into an
unlogged unpartitioned table. That got better by combining the loops in
CopyMultiInsertBufferFlush() (previously there were stalls due to the
indirect function calls for ExecCleartuple()). I think there's still a
tiny slowdown left in that scenario, but given that it's unlogged and
very narrow rows, I think that's ok.

Greetings,

Andres Freund