On Tue, May 18, 2021 at 2:32 PM Esteban Zimanyi <ezima...@ulb.ac.be> wrote: > > Dear all > > In MobilityDB we have defined parallel aggregations with a combine function, > e.g., > > CREATE AGGREGATE extent(tbox) ( > SFUNC = tbox_extent_transfn, > STYPE = tbox, > COMBINEFUNC = tbox_extent_combinefn, > PARALLEL = safe > ); > > We would like to trigger the combine functions in the coverage tests but for > this it is required that the tables are VERY big. In particular for the above > aggregation, the combine function only is triggered when the table has more > than 300K rows. > > As it is not very effective to have such a big table in the test database > used for the regression and the coverage tests I wonder whether it is > possible to set some parameters to launch the combine functions with tables > of, e.g., 10K rows, which are the bigger tables in our regression test > database. > > Many thanks for your insights !
You could do something like below, just before your test: -- encourage use of parallel plans set parallel_setup_cost=0; set parallel_tuple_cost=0; set min_parallel_table_scan_size=0; set max_parallel_workers_per_gather=2; And after the test you can reset all of the above parameters. Hope that helps! With Regards, Bharath Rupireddy. EnterpriseDB: http://www.enterprisedb.com
