Re: An idea for parallelizing COPY within one backend

Tom Lane wrote:

>"Florian G. Pflug" <fgp(at)phlo(dot)org> writes:
>
>
>>...
>>Neither the "dealer", nor the "workers" would need access to the either
>>the shared memory or the disk, thereby not messing with the "one backend
>>is one transaction is one session" dogma.
>>...
>>
>>
>
>Unfortunately, this idea has far too narrow a view of what a datatype
>input function might do. Just for starters, consider "enum" input,
>which certainly requires catalog access. We have also explicitly
>acknowledged the idea that datatype I/O functions might try to store
>typmod-related data in some special catalog somewhere.
>
> regards, tom lane
>
>
>
Would it be possible to determine when the copy is starting that this
case holds, and not use the parallel parsing idea in those cases?

I'm a big user of copy, generally into very simple tables- few indexes,
simple column types (numeric, varchar, and int almost exclusively), no
fancy features. A parallel copy input in the "simple" cases would be of
great advantage to me, even if it doesn't parallelize "complicated" cases.

Brian