Re: [sqlsmith] Parallel worker crash on seqscan - Mailing list pgsql-hackers

From Tom Lane
Subject Re: [sqlsmith] Parallel worker crash on seqscan
Date
Msg-id 28497.1479752734@sss.pgh.pa.us
Whole thread Raw
In response to Re: [sqlsmith] Parallel worker crash on seqscan  (Robert Haas <robertmhaas@gmail.com>)
List pgsql-hackers
Robert Haas <robertmhaas@gmail.com> writes:
> On Mon, Nov 21, 2016 at 1:00 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Hah: not where I thought it was at all.  The problem seems to be down to
>> the optimization I put into is_parallel_safe() awhile back to skip testing
>> anything if we previously found the entire querytree to be parallel-safe.
>> Well, the raw query tree *is* parallel-safe.  It's only when we inject
>> some Params that we have a parallel hazard.  So that optimization is too
>> optimistic :-(

> That sucks.  Any idea how we might salvage it?

I just disabled it by checking to see if any Params have been created.
It might be possible to be more refined, but I dunno that adding more
bookkeeping would pay for itself.
        regards, tom lane



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