389998 ?        Ss     0:00 postgres: tomas test [local] SELECT
 389999 ?        Ss     0:00 postgres: parallel worker for PID 389998 
 390000 ?        Ss     0:00 postgres: parallel worker for PID 389998 
 390001 ?        Ss     0:00 postgres: parallel worker for PID 389998 

leader

Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
0x00007fd253d29de3 in epoll_wait (epfd=5, events=0x5654911d9160, maxevents=1, timeout=timeout@entry=-1) at ../sysdeps/unix/sysv/linux/epoll_wait.c:30
30	../sysdeps/unix/sysv/linux/epoll_wait.c: No such file or directory.
(gdb) bt
#0  0x00007fd253d29de3 in epoll_wait (epfd=5, events=0x5654911d9160, maxevents=1, timeout=timeout@entry=-1) at ../sysdeps/unix/sysv/linux/epoll_wait.c:30
#1  0x00005654900206b9 in WaitEventSetWaitBlock (nevents=1, occurred_events=0x7fffadbf9360, cur_timeout=-1, set=0x5654911d90f8) at latch.c:1570
#2  WaitEventSetWait (set=0x5654911d90f8, timeout=timeout@entry=-1, occurred_events=occurred_events@entry=0x7fffadbf93a0, nevents=nevents@entry=1, wait_event_info=wait_event_info@entry=134217735) at latch.c:1516
#3  0x00005654900209a2 in WaitLatch (latch=<optimized out>, wakeEvents=wakeEvents@entry=33, timeout=timeout@entry=-1, wait_event_info=wait_event_info@entry=134217735) at latch.c:538
#4  0x000056549002ba6f in ConditionVariableTimedSleep (cv=cv@entry=0x7fd148250218, timeout=timeout@entry=-1, wait_event_info=wait_event_info@entry=134217735) at condition_variable.c:163
#5  0x000056549002bbfe in ConditionVariableSleep (cv=cv@entry=0x7fd148250218, wait_event_info=wait_event_info@entry=134217735) at condition_variable.c:98
#6  0x000056548fd71f9c in _bt_parallel_seize (scan=scan@entry=0x5654912e39f8, pageno=pageno@entry=0x7fffadbf94ac, first=first@entry=false) at nbtree.c:858
#7  0x000056548fd7340f in _bt_steppage (scan=scan@entry=0x5654912e39f8, dir=ForwardScanDirection) at nbtsearch.c:2214
#8  0x000056548fd73f81 in _bt_next (scan=scan@entry=0x5654912e39f8, dir=dir@entry=ForwardScanDirection) at nbtsearch.c:1592
#9  0x000056548fd70a98 in btgettuple (scan=0x5654912e39f8, dir=ForwardScanDirection) at nbtree.c:262
#10 0x000056548fd68891 in index_getnext_tid (scan=scan@entry=0x5654912e39f8, direction=direction@entry=ForwardScanDirection) at indexam.c:591
#11 0x000056548fd689db in index_getnext_slot (scan=scan@entry=0x5654912e39f8, direction=direction@entry=ForwardScanDirection, slot=slot@entry=0x5654912d37d0) at indexam.c:683
#12 0x000056548fed25ab in IndexNext (node=0x5654912d3540) at nodeIndexscan.c:130
#13 0x000056548fec9e11 in ExecProcNode (node=0x5654912d3540) at ../../../src/include/executor/executor.h:278
#14 gather_getnext (gatherstate=0x5654912d3368) at nodeGather.c:287
#15 ExecGather (pstate=0x5654912d3368) at nodeGather.c:222
#16 0x000056548feb0e5a in ExecProcNode (node=0x5654912d3368) at ../../../src/include/executor/executor.h:278
#17 ExecutePlan (execute_once=<optimized out>, dest=0x5654912dcd70, direction=<optimized out>, numberTuples=0, sendTuples=true, operation=CMD_SELECT, use_parallel_mode=<optimized out>, planstate=0x5654912d3368, estate=0x5654912d3128) at execMain.c:1641
#18 standard_ExecutorRun (queryDesc=0x5654912cf168, direction=<optimized out>, count=0, execute_once=<optimized out>) at execMain.c:358
#19 0x000056549004692f in PortalRunSelect (portal=portal@entry=0x56549125ba78, forward=forward@entry=true, count=0, count@entry=9223372036854775807, dest=dest@entry=0x5654912dcd70) at pquery.c:924
#20 0x0000565490047c27 in PortalRun (portal=portal@entry=0x56549125ba78, count=count@entry=9223372036854775807, isTopLevel=isTopLevel@entry=true, run_once=run_once@entry=true, dest=dest@entry=0x5654912dcd70, altdest=altdest@entry=0x5654912dcd70, 
    qc=0x7fffadbf9870) at pquery.c:768
#21 0x000056549004409c in exec_simple_query (query_string=0x5654911de188 "select * from t_1 where id in ( 41, 74, 7, 40);") at postgres.c:1284
#22 0x0000565490045b16 in PostgresMain (dbname=<optimized out>, username=<optimized out>) at postgres.c:4766
#23 0x00005654900409df in BackendMain (startup_data=<optimized out>, startup_data_len=<optimized out>) at backend_startup.c:107
#24 0x000056548ffb786b in postmaster_child_launch (child_type=child_type@entry=B_BACKEND, startup_data=startup_data@entry=0x7fffadbf9cfc "", startup_data_len=startup_data_len@entry=4, client_sock=client_sock@entry=0x7fffadbf9d00) at launch_backend.c:274
#25 0x000056548ffbaa53 in BackendStartup (client_sock=0x7fffadbf9d00) at postmaster.c:3415
#26 ServerLoop () at postmaster.c:1648
#27 0x000056548ffbc610 in PostmasterMain (argc=argc@entry=3, argv=argv@entry=0x5654911d8910) at postmaster.c:1346
#28 0x000056548fd12413 in main (argc=3, argv=0x5654911d8910) at main.c:197
(gdb) q

workers

0x00007fd253d29de3 in epoll_wait (epfd=5, events=0x5654911d9160, maxevents=1, timeout=timeout@entry=-1) at ../sysdeps/unix/sysv/linux/epoll_wait.c:30
30	../sysdeps/unix/sysv/linux/epoll_wait.c: No such file or directory.
(gdb) bt
#0  0x00007fd253d29de3 in epoll_wait (epfd=5, events=0x5654911d9160, maxevents=1, timeout=timeout@entry=-1) at ../sysdeps/unix/sysv/linux/epoll_wait.c:30
#1  0x00005654900206b9 in WaitEventSetWaitBlock (nevents=1, occurred_events=0x7fffadbf9850, cur_timeout=-1, set=0x5654911d90f8) at latch.c:1570
#2  WaitEventSetWait (set=0x5654911d90f8, timeout=timeout@entry=-1, occurred_events=occurred_events@entry=0x7fffadbf9890, nevents=nevents@entry=1, wait_event_info=wait_event_info@entry=134217764) at latch.c:1516
#3  0x00005654900209a2 in WaitLatch (latch=<optimized out>, wakeEvents=wakeEvents@entry=33, timeout=timeout@entry=0, wait_event_info=wait_event_info@entry=134217764) at latch.c:538
#4  0x0000565490026e11 in shm_mq_send_bytes (mqh=mqh@entry=0x56549126a3a0, nbytes=57, data=0x5654912b3920, nowait=nowait@entry=false, bytes_written=bytes_written@entry=0x7fffadbf9970) at shm_mq.c:1018
#5  0x00005654900272b4 in shm_mq_sendv (mqh=0x56549126a3a0, iov=iov@entry=0x7fffadbf99c0, iovcnt=iovcnt@entry=1, nowait=nowait@entry=false, force_flush=force_flush@entry=false) at shm_mq.c:493
#6  0x00005654900274a1 in shm_mq_send (mqh=<optimized out>, nbytes=<optimized out>, data=data@entry=0x5654912b3920, nowait=nowait@entry=false, force_flush=force_flush@entry=false) at shm_mq.c:337
#7  0x000056548feeb4b9 in tqueueReceiveSlot (slot=<optimized out>, self=0x565491269098) at tqueue.c:63
#8  0x000056548feb0e8c in ExecutePlan (execute_once=<optimized out>, dest=0x565491269098, direction=<optimized out>, numberTuples=0, sendTuples=true, operation=CMD_SELECT, use_parallel_mode=<optimized out>, planstate=0x5654912b27d0, 
    estate=0x5654912b2558) at execMain.c:1672
#9  standard_ExecutorRun (queryDesc=0x56549126ab18, direction=<optimized out>, count=0, execute_once=<optimized out>) at execMain.c:358
#10 0x000056548feb5187 in ParallelQueryMain (seg=0x5654912118d8, toc=0x7fd2543ae000) at execParallel.c:1472
#11 0x000056548fd9839b in ParallelWorkerMain (main_arg=<optimized out>) at parallel.c:1524
#12 0x000056548ffb574e in BackgroundWorkerMain (startup_data=<optimized out>, startup_data_len=<optimized out>) at bgworker.c:842
#13 0x000056548ffb786b in postmaster_child_launch (child_type=child_type@entry=B_BG_WORKER, startup_data=startup_data@entry=0x56549120b4a0 "parallel worker for PID 389998", startup_data_len=startup_data_len@entry=1472, client_sock=client_sock@entry=0x0)
    at launch_backend.c:274
#14 0x000056548ffb93ee in do_start_bgworker (rw=0x56549120b4a0) at postmaster.c:3916
#15 maybe_start_bgworkers () at postmaster.c:4123
#16 0x000056548ffba207 in LaunchMissingBackgroundProcesses () at postmaster.c:3237
#17 ServerLoop () at postmaster.c:1663
#18 0x000056548ffbc610 in PostmasterMain (argc=argc@entry=3, argv=argv@entry=0x5654911d8910) at postmaster.c:1346
#19 0x000056548fd12413 in main (argc=3, argv=0x5654911d8910) at main.c:197

Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
0x00007fd253d29de3 in epoll_wait (epfd=5, events=0x5654911d9160, maxevents=1, timeout=timeout@entry=-1) at ../sysdeps/unix/sysv/linux/epoll_wait.c:30
30	../sysdeps/unix/sysv/linux/epoll_wait.c: No such file or directory.
(gdb) bt
#0  0x00007fd253d29de3 in epoll_wait (epfd=5, events=0x5654911d9160, maxevents=1, timeout=timeout@entry=-1) at ../sysdeps/unix/sysv/linux/epoll_wait.c:30
#1  0x00005654900206b9 in WaitEventSetWaitBlock (nevents=1, occurred_events=0x7fffadbf97a0, cur_timeout=-1, set=0x5654911d90f8) at latch.c:1570
#2  WaitEventSetWait (set=0x5654911d90f8, timeout=timeout@entry=-1, occurred_events=occurred_events@entry=0x7fffadbf97e0, nevents=nevents@entry=1, wait_event_info=wait_event_info@entry=134217735) at latch.c:1516
#3  0x00005654900209a2 in WaitLatch (latch=<optimized out>, wakeEvents=wakeEvents@entry=33, timeout=timeout@entry=-1, wait_event_info=wait_event_info@entry=134217735) at latch.c:538
#4  0x000056549002ba6f in ConditionVariableTimedSleep (cv=cv@entry=0x7fd2543ae218, timeout=timeout@entry=-1, wait_event_info=wait_event_info@entry=134217735) at condition_variable.c:163
#5  0x000056549002bbfe in ConditionVariableSleep (cv=cv@entry=0x7fd2543ae218, wait_event_info=wait_event_info@entry=134217735) at condition_variable.c:98
#6  0x000056548fd71f9c in _bt_parallel_seize (scan=scan@entry=0x565491269d98, pageno=pageno@entry=0x7fffadbf98ec, first=first@entry=false) at nbtree.c:858
#7  0x000056548fd7340f in _bt_steppage (scan=scan@entry=0x565491269d98, dir=ForwardScanDirection) at nbtsearch.c:2214
#8  0x000056548fd73f81 in _bt_next (scan=scan@entry=0x565491269d98, dir=dir@entry=ForwardScanDirection) at nbtsearch.c:1592
#9  0x000056548fd70a98 in btgettuple (scan=0x565491269d98, dir=ForwardScanDirection) at nbtree.c:262
#10 0x000056548fd68891 in index_getnext_tid (scan=scan@entry=0x565491269d98, direction=direction@entry=ForwardScanDirection) at indexam.c:591
#11 0x000056548fd689db in index_getnext_slot (scan=scan@entry=0x565491269d98, direction=direction@entry=ForwardScanDirection, slot=slot@entry=0x5654912b2f08) at indexam.c:683
#12 0x000056548fed25ab in IndexNext (node=0x5654912b27d0) at nodeIndexscan.c:130
#13 0x000056548feb0e5a in ExecProcNode (node=0x5654912b27d0) at ../../../src/include/executor/executor.h:278
#14 ExecutePlan (execute_once=<optimized out>, dest=0x565491269098, direction=<optimized out>, numberTuples=0, sendTuples=true, operation=CMD_SELECT, use_parallel_mode=<optimized out>, planstate=0x5654912b27d0, estate=0x5654912b2558) at execMain.c:1641
#15 standard_ExecutorRun (queryDesc=0x56549126ab18, direction=<optimized out>, count=0, execute_once=<optimized out>) at execMain.c:358
#16 0x000056548feb5187 in ParallelQueryMain (seg=0x5654912118d8, toc=0x7fd2543ae000) at execParallel.c:1472
#17 0x000056548fd9839b in ParallelWorkerMain (main_arg=<optimized out>) at parallel.c:1524
#18 0x000056548ffb574e in BackgroundWorkerMain (startup_data=<optimized out>, startup_data_len=<optimized out>) at bgworker.c:842
#19 0x000056548ffb786b in postmaster_child_launch (child_type=child_type@entry=B_BG_WORKER, startup_data=startup_data@entry=0x56549120ac98 "parallel worker for PID 389998", startup_data_len=startup_data_len@entry=1472, client_sock=client_sock@entry=0x0)
    at launch_backend.c:274
#20 0x000056548ffb93ee in do_start_bgworker (rw=0x56549120ac98) at postmaster.c:3916
#21 maybe_start_bgworkers () at postmaster.c:4123
#22 0x000056548ffba207 in LaunchMissingBackgroundProcesses () at postmaster.c:3237
#23 ServerLoop () at postmaster.c:1663
#24 0x000056548ffbc610 in PostmasterMain (argc=argc@entry=3, argv=argv@entry=0x5654911d8910) at postmaster.c:1346
#25 0x000056548fd12413 in main (argc=3, argv=0x5654911d8910) at main.c:197

Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
0x00007fd253d29de3 in epoll_wait (epfd=5, events=0x5654911d9160, maxevents=1, timeout=timeout@entry=-1) at ../sysdeps/unix/sysv/linux/epoll_wait.c:30
30	../sysdeps/unix/sysv/linux/epoll_wait.c: No such file or directory.
(gdb) bt
#0  0x00007fd253d29de3 in epoll_wait (epfd=5, events=0x5654911d9160, maxevents=1, timeout=timeout@entry=-1) at ../sysdeps/unix/sysv/linux/epoll_wait.c:30
#1  0x00005654900206b9 in WaitEventSetWaitBlock (nevents=1, occurred_events=0x7fffadbf9850, cur_timeout=-1, set=0x5654911d90f8) at latch.c:1570
#2  WaitEventSetWait (set=0x5654911d90f8, timeout=timeout@entry=-1, occurred_events=occurred_events@entry=0x7fffadbf9890, nevents=nevents@entry=1, wait_event_info=wait_event_info@entry=134217764) at latch.c:1516
#3  0x00005654900209a2 in WaitLatch (latch=<optimized out>, wakeEvents=wakeEvents@entry=33, timeout=timeout@entry=0, wait_event_info=wait_event_info@entry=134217764) at latch.c:538
#4  0x0000565490026e11 in shm_mq_send_bytes (mqh=mqh@entry=0x56549126a3a0, nbytes=57, data=0x5654912b3920, nowait=nowait@entry=false, bytes_written=bytes_written@entry=0x7fffadbf9970) at shm_mq.c:1018
#5  0x00005654900272b4 in shm_mq_sendv (mqh=0x56549126a3a0, iov=iov@entry=0x7fffadbf99c0, iovcnt=iovcnt@entry=1, nowait=nowait@entry=false, force_flush=force_flush@entry=false) at shm_mq.c:493
#6  0x00005654900274a1 in shm_mq_send (mqh=<optimized out>, nbytes=<optimized out>, data=data@entry=0x5654912b3920, nowait=nowait@entry=false, force_flush=force_flush@entry=false) at shm_mq.c:337
#7  0x000056548feeb4b9 in tqueueReceiveSlot (slot=<optimized out>, self=0x565491269098) at tqueue.c:63
#8  0x000056548feb0e8c in ExecutePlan (execute_once=<optimized out>, dest=0x565491269098, direction=<optimized out>, numberTuples=0, sendTuples=true, operation=CMD_SELECT, use_parallel_mode=<optimized out>, planstate=0x5654912b27d0, 
    estate=0x5654912b2558) at execMain.c:1672
#9  standard_ExecutorRun (queryDesc=0x56549126ab18, direction=<optimized out>, count=0, execute_once=<optimized out>) at execMain.c:358
#10 0x000056548feb5187 in ParallelQueryMain (seg=0x5654912118d8, toc=0x7fd2543ae000) at execParallel.c:1472
#11 0x000056548fd9839b in ParallelWorkerMain (main_arg=<optimized out>) at parallel.c:1524
#12 0x000056548ffb574e in BackgroundWorkerMain (startup_data=<optimized out>, startup_data_len=<optimized out>) at bgworker.c:842
#13 0x000056548ffb786b in postmaster_child_launch (child_type=child_type@entry=B_BG_WORKER, startup_data=startup_data@entry=0x56549120a490 "parallel worker for PID 389998", startup_data_len=startup_data_len@entry=1472, client_sock=client_sock@entry=0x0)
    at launch_backend.c:274
#14 0x000056548ffb93ee in do_start_bgworker (rw=0x56549120a490) at postmaster.c:3916
#15 maybe_start_bgworkers () at postmaster.c:4123
#16 0x000056548ffba207 in LaunchMissingBackgroundProcesses () at postmaster.c:3237
#17 ServerLoop () at postmaster.c:1663
#18 0x000056548ffbc610 in PostmasterMain (argc=argc@entry=3, argv=argv@entry=0x5654911d8910) at postmaster.c:1346
#19 0x000056548fd12413 in main (argc=3, argv=0x5654911d8910) at main.c:197