Re: [COMMITTERS] pgsql: Don't generate parallel paths for rels with parallel-restricted

Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> On Thu, Jun 9, 2016 at 1:02 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> It seems like the only reason that we would need such a flag is that
>> applying has_parallel_hazard() to a Var is a bit expensive thanks to
>> the typeid_is_temp() test --- but if you ask me, that test is stupid
>> and should be removed. What's the argument for supposing that a temp
>> table's rowtype is any more mutable intra-query than any other rowtype?

> That error is coming from relation_open(). It might be possible to
> find a way to nerf the check in relation_open() enough to let this
> case work while making the cases that we need to fail still fail,

Well, yeah, you could remove it. It's inappropriate. The right place
for such an error check is an attempt to actually access any data within
a temp table, ie someplace in localbuf.c. There is no reason a worker
shouldn't be allowed to look at the catalog entries for a temp table;
they're just like any other catalog entries.

regards, tom lane