#0  WaitLatchOrSocket (latch=0x7f6d848679a4, wakeEvents=17, sock=-1, timeout=-1) at latch.c:322
#1  0x0000000000b5fb6d in WaitLatch (latch=0x7f6d848679a4, wakeEvents=17, timeout=-1) at latch.c:303
#2  0x0000000000d4c5c8 in waitOnGroup (group=0x7f6d84800928, isMoveQuery=0 '\000') at resgroup.c:2918
#3  0x0000000000d4ada6 in groupAcquireSlot (pGroupInfo=0x7ffd422a3d70, isMoveQuery=0 '\000') at resgroup.c:1934
#4  0x0000000000d4bd7b in AssignResGroupOnMaster () at resgroup.c:2636
#5  0x0000000000787133 in StartTransaction () at xact.c:2606
#6  0x00000000007881a4 in StartTransactionCommand () at xact.c:3576
#7  0x0000000000b8f77c in start_xact_command ()	at postgres.c:3183
#8  0x0000000000b8cdb6 in exec_simple_query (query_string=0x31090e0 "select * from region limit 1;") at postgres.c:1573
#9  0x0000000000b91ca3 in PostgresMain (argc=1,	argv=0x3107220,	dbname=0x31070f8 "tpch1s", username=0x31070e0 "yz") at postgres.c:5085
……