Re: Parallel Seq Scan

On Wed, Oct 14, 2015 at 3:29 AM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>
> On Tue, Oct 13, 2015 at 2:45 AM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>
wrote:
> > Attached is rebased patch for partial seqscan support.
>
> Review comments:
>
>
> - I continue to think GetParallelShmToc is the wrong approach.
> Instead, each time ExecParallelInitializeDSM or
> ExecParallelInitializeDSM calls a nodetype-specific initialized
> function (as described in the previous point), have it pass d->pcxt as
> an argument. The node can get the toc from there if it needs it. I
> suppose it could store a pointer to the toc in its scanstate if it
> needs it, but it really shouldn't. Instead, it should store a pointer
> to, say, the ParallelHeapScanDesc in the scanstate.
>

How will this idea work for worker backend. Basically in worker
if want something like this to work, toc has to be passed via
QueryDesc to Estate and then we can retrieve ParallelHeapScanDesc
during PartialSeqScan initialization (ExecInitPartialSeqScan).
Do you have something else in mind?

With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com