Re: Parallel Seq Scan - Mailing list pgsql-hackers

On Tue, Jan 20, 2015 at 9:43 PM, Thom Brown <thom@linux.com> wrote:
>
> On 20 January 2015 at 14:29, Amit Kapila <amit.kapila16@gmail.com> wrote:
>>
>> On Thu, Jan 15, 2015 at 6:57 PM, Amit Kapila <amit.kapila16@gmail.com> wrote:
>> > On Mon, Jan 12, 2015 at 3:25 AM, Robert Haas <robertmhaas@gmail.com> wrote:
>> > >
>> > > Yeah, you need two separate global variables pointing to shm_mq
>> > > objects, one of which gets used by pqmq.c for errors and the other of
>> > > which gets used by printtup.c for tuples.
>> > >
>> >
>> > Okay, I will try to change the way as suggested without doing
>> > switching, but this way we need to do it separately for 'T', 'D', and
>> > 'C' messages.
>> >
>>
>> I have taken care of integrating the parallel sequence scan with the
>> latest patch posted (parallel-mode-v1.patch) by Robert at below
>> location:
>> http://www.postgresql.org/message-id/CA+TgmoZdUK4K3XHBxc9vM-82khourEZdvQWTfgLhWsd2R2aAGQ@mail.gmail.com
>>
>> Changes in this version
>> -----------------------------------------------
>> 1. As mentioned previously, I have exposed one parameter
>> ParallelWorkerNumber as used in parallel-mode patch.
>> 2. Enabled tuple queue to be used for passing tuples from
>> worker backend to master backend along with error queue
>> as per suggestion by Robert in the mail above.
>> 3. Involved master backend to scan the heap directly when
>> tuples are not available in any shared memory tuple queue.
>> 4. Introduced 3 new parameters (cpu_tuple_comm_cost,
>> parallel_setup_cost, parallel_startup_cost) for deciding the cost
>> of parallel plan.  Currently, I have kept the default values for
>> parallel_setup_cost and parallel_startup_cost as 0.0, as those
>> require some experiments.
>> 5. Fixed some issues (related to memory increase as reported
>> upthread by Thom Brown and general feature issues found during
>> test)
>>
>> Note - I have yet to handle the new node types introduced at some
>> of the places and need to verify prepared queries and some other
>> things, however I think it will be good if I can get some feedback
>> at current stage.
>
>
> Which commit is this based against?  I'm getting errors with the latest master:
>