Re: Split copy.c

On Tue, Nov 03, 2020 at 03:15:27PM +1300, David Rowley wrote:
> On Tue, 3 Nov 2020 at 07:35, Andres Freund <andres(at)anarazel(dot)de> wrote:
> >
> > On 2020-11-02 19:43:38 +0200, Heikki Linnakangas wrote:
> > > On 02/11/2020 19:23, Andres Freund wrote:
> > > > On 2020-11-02 11:03:29 +0200, Heikki Linnakangas wrote:
> > > > > There isn't much common code between COPY FROM and COPY TO, so I propose
> > > > > that we split copy.c into two: copyfrom.c and copyto.c. See attached. I thin
> > > > > that's much nicer.
> > > >
> > > > Not quite convinced that's the right split - or perhaps there's just
> > > > more potential. My feeling is that splitting out all the DML related
> > > > code would make the code considerably easier to read.
> > >
> > > What do you mean by DML related code?
> >
> > Basically all the insertion related code (e.g CopyMultiInsert*, lots of
> > code in CopyFrom()) and perhaps also the type input invocations.
>
> I quite like the fact that those are static and inline-able. I very
> much imagine there'd be a performance hit if we moved them out to
> another .c file and made them extern. Some of those functions can be
> quite hot when copying into a partitioned table.

For another patch [0], I moved into copy.h:
+typedef struct CopyMultiInsertBuffer
+typedef struct CopyMultiInsertInfo
+CopyMultiInsertBufferInit(ResultRelInfo *rri)
+CopyMultiInsertInfoSetupBuffer(CopyMultiInsertInfo *miinfo,
+CopyMultiInsertInfoIsFull(CopyMultiInsertInfo *miinfo)
+CopyMultiInsertBufferCleanup(CopyMultiInsertInfo *miinfo,
+CopyMultiInsertInfoNextFreeSlot(CopyMultiInsertInfo *miinfo,
+CopyMultiInsertInfoStore(CopyMultiInsertInfo *miinfo, ResultRelInfo *rri,

That's an experimental part 0002 of my patch in response to Simon's suggestion.
Maybe your response will be that variants of those interfaces should be added
to nodeModifyTable.[ch] instead of moving them. Currently I'm passing
(void*)mtstate as cstate - if there were a generic interface, that would be a
void *state or so.

[0] https://commitfest.postgresql.org/30/2553/
should INSERT SELECT use a BulkInsertState? (and multi_insert)

--
Justin