It should not be possible because a group does not return to the update pool before the update hasn't finished. I watched the queries in a postgres client and there was no overlap I could see. I don't really know what to make from this behavior, sometimes when I start the application a few updates go through and eventually it will lock up completely and sometimes it locks up immediately - always with heap_hot_search_buffer using ~20 of all CPU time on the system. 2016-11-24 19:14 GMT+01:00 Adrian Klaver <adrian.klaver@xxxxxxxxxxx>: > On 11/23/2016 10:41 PM, azhwkd wrote: >> >> The group ID is part of the primary key of the group_history table. My >> understanding is that two INSERTs with different group IDs should not >> collide in this case, or am I wrong in thinking this? > > > After fresh coffee: > > In your first post you had this: > "(In the application this > query is run up to 10 times in parallel with different parameters)" > > where the parameters look to be a timestamp and a group id. > > Is it possible that the combination of parameters over the 10 different > queries is not actually selecting rows in each result set that are unique > over (group,id,sub_category,"date","hour") between result sets? > > > > >> >> The table definition for group_history is the following: >> >> CREATE TABLE public.group_history ( >> group int4 NOT NULL, >> id int4 NOT NULL, >> sub_category int4 NOT NULL, >> "date" date NOT NULL, >> aa int8 NOT NULL, >> ab int8 NOT NULL, >> bb int8 NOT NULL, >> ba int8 NOT NULL, >> quantity int8 NOT NULL, >> "hour" int2 NOT NULL, >> CONSTRAINT group_history_pk PRIMARY KEY >> (group,id,sub_category,"date","hour") >> ) >> WITH ( >> OIDS=FALSE >> ); >> >> Kind regards, >> Sebastian >> > > > > -- > Adrian Klaver > adrian.klaver@xxxxxxxxxxx -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
