> On 9. Jun 2020, at 21:30, Michael Lewis <mle...@entrata.com> wrote: > >> On Tue, Jun 9, 2020 at 12:34 PM Sebastian Dressler <sebast...@swarm64.com> >> wrote: >> - Add an index on top of the whole PK >> - Add indexes onto other columns trying to help the JOIN >> - Add additional statistics on two related columns >> >> Another idea I had was to make use of generated columns and hash the PKs >> together to an BIGINT and solely use this for the JOIN. However, this would >> not work when not all columns of the PK are used for the JOIN. > > Can you expand on the additional statistics you created? Why was it on only > two columns? Did you include MCVs type of extended stats?
Sure, for the MCVs specifically I tried to select which columns belong together to also have value for the end-user when running a query. Basically in accordance what the docs suggest, i.e. [1] section 14.2.2.3 last paragraph. Given the nature of the data I however think this can be very difficult to do without requiring further user input. Likewise, as the others suggested, it did not help for this particular case. Cheers, Sebastian [1]: https://www.postgresql.org/docs/current/planner-stats.html#PLANNER-STATS-EXTENDED -- Sebastian Dressler, Solution Architect +49 30 994 0496 72 | sebast...@swarm64.com Swarm64 AS Parkveien 41 B | 0258 Oslo | Norway Registered at Brønnøysundregistrene in Norway under Org.-Number 911 662 787 CEO/Geschäftsführer (Daglig Leder): Thomas Richter; Chairman/Vorsitzender (Styrets Leder): Dr. Sverre Munck Swarm64 AS Zweigstelle Hive Ullsteinstr. 120 | 12109 Berlin | Germany Registered at Amtsgericht Charlottenburg - HRB 154382 B
