Re: ERROR: XX000: cannot update SecondarySnapshot during a paralleloperation

On 3/13/19 10:54 PM, fuzk wrote:
> Dear Adrian,
> 
> My setting is as following.
> 
> max_parallel_workers_per_gather=32

Not sure if it is possible without affecting other operations, but you 
could set the above to 0 to temporarily disable parallel queries and see 
if that eliminates the error.

Also see:

https://trac.osgeo.org/postgis/ticket/4129

> 
> I am looking forward to hearing from you.
> 
> Many thanks
> Alan.
> 
> 
> 
> 
> 
> 
> 
> At 2019-03-13 22:31:11, "Adrian Klaver" <adrian.klaver@aklaver.com> wrote:
>>On 3/12/19 7:54 PM, fuzk wrote:
>>> Dear Sir/Madam
>>> 
>>> I got an error when I execute the following select sentence.
>>> Would you please solve the problem for me?
>>
>>What version of Postgres?
>>
>>> Thank you .
>>> 
>>> Alan Fu.
>>> 
>>> postgres=# \set VERBOSITY verbose
>>> postgres=# SELECT 
>>> round(cast(coalesce(sum(ST_length(geography(geometry)))/1000,0) as 
>>> NUMERIC),4)||'KM' field_value from had_link;
>>> 
>>> ERROR:  XX000: cannot update SecondarySnapshot during a parallel operation
>>> CONTEXT:  SQL statement "SELECT proj4text FROM public.spatial_ref_sys 
>>> WHERE srid = 4326 LIMIT 1"
>>> parallel worker
>>> LOCATION:  GetLatestSnapshot, snapmgr.c:387
>>
>>I'm guessing ST_length is not parallel safe.
>>
>>What is your setting for?:
>>
>>max_parallel_workers_per_gather
>>
>>> 
>>> 
>>
>>
>>-- 
>>Adrian Klaver
>>adrian.klaver@aklaver.com
> 
> 
> 


-- 
Adrian Klaver
adrian.klaver@aklaver.com