Horton

Re: [BUGS] [postgresql 10 beta3] unrecognized node type: 90

Amit Kapila <amit.kapila16@gmail.com>

View thread View on postgr.es
From: Amit Kapila <amit.kapila16@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Robert Haas <robertmhaas@gmail.com>, Noah Misch <noah@leadboat.com>, "Adam, Etienne (Nokia-TECH/Issy Les Moulineaux)" <etienne.adam@nokia.com>, PostgreSQL Bugs <pgsql-bugs@postgresql.org>, "Duquesne, Pierre (Nokia-TECH/Issy Les Moulineaux)" <pierre.duquesne@nokia.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2017-08-28T12:44:51Z
Lists: pgsql-bugs, pgsql-hackers 
On Mon, Aug 28, 2017 at 6:01 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Amit Kapila <amit.kapila16@gmail.com> writes:
>> With this change, it is quite possible that during rescans workers
>> will not do any work.
>
> Um, what's different about that than before?
>

Earlier, we perform the rescan of all the nodes before ExecProcNode,
so workers will always start (restart) after the scan descriptor is
initialized.  Now, as evident in the discussion in this thread that
was not the right thing for gather merge as some of the nodes like
Sort does some optimization due to which rescan for the lower nodes
will never be called.  So, we need to ensure in some way that we don't
skip rescanning in such nodes and one way to achieve that is what you
have done in the patch, but it seems to have some side effect.


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

Commits

  1. Separate reinitialization of shared parallel-scan state from ExecReScan.

  2. Restore test case from a2b70c89ca1a5fcf6181d3c777d82e7b83d2de1b.

  3. Force rescanning of parallel-aware scan nodes below a Gather[Merge].

  4. Fix ExecReScanGatherMerge.

  5. Add missing call to ExecReScanGatherMerge.