max_parallel_workers_per_gather=2 ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Test NO | test case | query plan | patched(ms) | master(ms) | %reg ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ 1 | Test INSERT with underlying query. | parallel INSERT+SELECT | 20894.069 | 27030.623 | -23% 2 | Test INSERT into a table with a foreign key. | parallel SELECT | 80921.960 | 84416.775 | -4% 3 | Test INSERT with ON CONFLICT ... DO UPDATE | non-parallel | 28111.186 | 29531.922 | -5% 4 | Test INSERT with parallel_leader_participation = off; | parallel INSERT+SELECT | 2799.354 | 5131.874 | -45% 5 | Test INSERT with max_parallel_workers=0; | non-parallel | 27006.385 | 26962.279 | 0% 6 | Test INSERT with parallelized aggregate | parallel SELECT | 95482.307 | 105090.301 | -9% 7 | Test INSERT with parallel bitmap heap scan | parallel INSERT+SELECT | 606.664 | 844.471 | -28% 8 | Test INSERT with parallel append | parallel INSERT+SELECT | 109.896 | 239.198 | -54% 9 | Test INSERT with parallel index scan | parallel INSERT+SELECT | 552.481 | 1238.079 | -55% 10 | Test INSERT with parallel-safe index expression | parallel INSERT+SELECT | 1453.686 | 2908.489 | -50% 11 | Test INSERT with parallel-unsafe index expression | non-parallel | 2828.559 | 2837.570 | 0% 12 | Test INSERT with underlying query - and RETURNING (no projection) | parallel INSERT+SELECT | 417.493 | 685.430 | -39% 13 | Test INSERT with underlying ordered query - and RETURNING (no projection) | parallel SELECT | 971.095 | 1717.502 | -43% 14 | Test INSERT with underlying ordered query - and RETURNING (with projection) | parallel SELECT | 1002.287 | 1745.255 | -43% 15 | Test INSERT into temporary table with underlying query. | parallel SELECT | 224.420 | 489.748 | -54% 16 | No column defaults, should use parallel INSERT+SELECT | parallel INSERT+SELECT | 1520.582 | 1856.966 | -18% 17 | Parallel unsafe column default, should not use a parallel plan | non-parallel | 2260.880 | 2251.054 | 0% 18 | Parallel restricted column default, should use INSERT + parallel SELECT | parallel SELECT | 1975.598 | 2249.041 | -12% 19 | Parallel safe column default, should use parallel INSERT+SELECT | parallel INSERT+SELECT | 1624.270 | 2245.439 | -28% 20 | Parallel restricted and unsafe column defaults, should not use a parallel plan | non-parallel | 2411.253 | 2517.183 | -4% 21 | Test INSERT into partition with underlying query. | parallel INSERT+SELECT | 4620.209 | 9533.214 | -52% 22 | Test INSERT into partition with parallel-unsafe partition key expression | non-parallel | 11961.355 | 11724.563 | 2% 23 | Test INSERT into table with parallel-safe check constraint | parallel INSERT+SELECT | 3917.872 | 8939.580 | -56% 24 | Test INSERT into table with parallel-unsafe check constraint | non-parallel | 9249.216 | 9157.939 | 1% 25 | Test INSERT into table with before+after parallel-safe stmt-level triggers | parallel INSERT+SELECT | 549.534 | 969.528 | -43% 26 | Test INSERT into table with before+after parallel-unsafe stmt-level triggers | non-parallel | 947.072 | 967.843 | -2% 27 | Test INSERT into table with before+after parallel-restricted stmt-level trigger | parallel SELECT | 682.345 | 967.293 | -29% 28 | Test INSERT into table with TOAST column | parallel INSERT+SELECT | 230.174 | 319.134 | -28% 29 | Test INSERT into table having a DOMAIN column with parallel-unsafe CHECK constraint | non-parallel | 9826.738 | 9985.930 | -2% 30 | Test INSERT into table having a DOMAIN column with parallel-restricted CHECK constraint | parallel SELECT | 3743.854 | 8731.420 | -57% 31 | Test INSERT into table having a DOMAIN column with parallel-safe CHECK constraint | parallel SELECT | 3757.773 | 8736.047 | -57% 32 | Test INSERT with ordered underlying query. | parallel SELECT | 4982.904 | 9347.244 | -47% 33 | Test INSERT into foreign table with underlying query. | parallel SELECT | 11728.190 | 11823.020 | -1%