2018-05-17 11:32 GMT+02:00 Pavel Stehule <pavel.steh...@gmail.com>: > Hi > > just for curiosity - I tested simple script > > postgres=# do > $$ > declare s bigint = 0; > begin > for i in 1..1000000000 loop > s := s + i; > end loop; > raise notice '%', s; > end; > $$; > > to see a overhead of some components > > 5,72% plpgsql.so [.] exec_assign_value > 5,59% postgres [.] GetSnapshotData > 4,94% plpgsql.so [.] exec_eval_simple_expr > 4,84% postgres [.] AllocSetAlloc > 3,61% postgres [.] > ResourceOwnerForgetPlanCacheRef > 2,95% postgres [.] choose_custom_plan > 2,94% postgres [.] GetUserId > 2,92% postgres [.] GetCachedPlan > 2,87% postgres [.] LWLockAttemptLock > 2,85% postgres [.] memset@plt > 2,76% postgres [.] LWLockRelease > 2,70% postgres [.] AllocSetFree > 2,42% plpgsql.so [.] assign_simple_var > 2,36% postgres [.] ExecInterpExpr > 2,35% postgres [.] PopActiveSnapshot > 2,27% postgres [.] > OverrideSearchPathMatchesCurrent > 2,22% plpgsql.so [.] > plpgsql_param_eval_var > 2,21% plpgsql.so [.] exec_stmt > 1,89% libc-2.27.so [.] > __memset_sse2_unaligned_erms > 1,75% postgres [.] PushActiveSnapshot > 1,74% postgres [.] AcquireExecutorLocks > 1,67% postgres [.] CopySnapshot > 1,64% postgres [.] CheckCachedPlan > 1,56% postgres [.] RevalidateCachedQuery > 1,55% postgres [.] MemoryContextAlloc > 1,53% postgres [.] pfree > 1,50% postgres [.] ResourceArrayRemove > 1,43% postgres [.] LWLockAcquire > 1,40% postgres [.] > SPI_plan_get_cached_plan > > maybe we need some new kind of function, that doesn't requires snapshots, user info, locks - and the plan can be stored directly instead using plan cache.
Hard to believe, what necessary be done before we want to calculate two numbers. Regards Pavel > Regards > > Pavel >
