#0  0x00007308e8e06e35 in raise () from /lib64/libc.so.6
#1  0x00007308e8df1895 in abort () from /lib64/libc.so.6
#2  0x00000000008c2aeb in ExceptionalCondition (conditionName=conditionName@entry=0x9f8583 "nbuckets > 0", errorType=errorType@entry=0x915029 "FailedAssertion", fileName=fileName@entry=0x9f84b7 "execGrouping.c", 
    lineNumber=lineNumber@entry=174) at assert.c:67
#3  0x000000000063f704 in BuildTupleHashTableExt (parent=parent@entry=0x2344538, inputDesc=<optimized out>, numCols=<optimized out>, keyColIdx=keyColIdx@entry=0x23614b0, eqfuncoids=0x2361528, hashfunctions=<optimized out>, 
    collations=0x232f130, nbuckets=0, additionalsize=16, metacxt=0x23461f0, tablecxt=0x23461f0, tempcxt=0x233e1b0, use_variable_hash_iv=false) at execGrouping.c:174
#4  0x00000000006534d1 in build_hash_table (aggstate=aggstate@entry=0x2344538, setno=<optimized out>, nbuckets=<optimized out>) at nodeAgg.c:1476
#5  0x000000000065504b in agg_refill_hash_table (aggstate=0x2344538) at nodeAgg.c:2474
#6  agg_retrieve_hash_table (aggstate=0x2344538) at nodeAgg.c:2594
#7  0x000000000065588d in agg_retrieve_direct (aggstate=<optimized out>) at nodeAgg.c:2141
#8  ExecAgg (pstate=<optimized out>) at nodeAgg.c:2022
#9  0x0000000000648579 in ExecProcNodeInstr (node=0x2344538) at execProcnode.c:460
#10 0x000000000064116b in ExecProcNode (node=0x2344538) at ../../../src/include/executor/executor.h:245
#11 ExecutePlan (execute_once=<optimized out>, dest=0xa39c00 <donothingDR>, direction=<optimized out>, numberTuples=0, sendTuples=<optimized out>, operation=CMD_SELECT, use_parallel_mode=<optimized out>, planstate=0x2344538, 
    estate=0x2344300) at execMain.c:1646
#12 standard_ExecutorRun (queryDesc=0x23308a0, direction=<optimized out>, count=0, execute_once=<optimized out>) at execMain.c:364
#13 0x00000000005daea9 in ExplainOnePlan (plannedstmt=plannedstmt@entry=0x2330788, into=into@entry=0x0, es=es@entry=0x232dd40, queryString=queryString@entry=0x22617b0 "explain analyze select a, b, sum(c) from t2 group by 1, 2;", 
    params=params@entry=0x0, queryEnv=queryEnv@entry=0x0, planduration=0x7ffdc444edc0) at explain.c:549
#14 0x00000000005db1d5 in ExplainOneQuery (queryEnv=0x0, params=0x0, queryString=0x22617b0 "explain analyze select a, b, sum(c) from t2 group by 1, 2;", es=0x232dd40, into=0x0, cursorOptions=<optimized out>, query=<optimized out>)
    at explain.c:385
#15 ExplainOneQuery (query=<optimized out>, cursorOptions=<optimized out>, into=0x0, es=0x232dd40, queryString=0x22617b0 "explain analyze select a, b, sum(c) from t2 group by 1, 2;", params=0x0, queryEnv=0x0) at explain.c:353
#16 0x00000000005db79e in ExplainQuery (pstate=pstate@entry=0x22cb5d0, stmt=stmt@entry=0x22629b0, params=params@entry=0x0, dest=dest@entry=0x22cb538) at ../../../src/include/nodes/nodes.h:590
#17 0x00000000007b47d3 in standard_ProcessUtility (pstmt=0x2262b28, queryString=0x22617b0 "explain analyze select a, b, sum(c) from t2 group by 1, 2;", context=PROCESS_UTILITY_TOPLEVEL, params=0x0, queryEnv=0x0, dest=0x22cb538, 
    completionTag=0x7ffdc444ef60 "") at utility.c:836
#18 0x00000000007b1986 in PortalRunUtility (portal=0x22c73e0, pstmt=0x2262b28, isTopLevel=<optimized out>, setHoldSnapshot=<optimized out>, dest=0x22cb538, completionTag=0x7ffdc444ef60 "") at pquery.c:1175
#19 0x00000000007b28b0 in FillPortalStore (portal=0x22c73e0, isTopLevel=<optimized out>) at ../../../src/include/nodes/nodes.h:590
#20 0x00000000007b3405 in PortalRun (portal=portal@entry=0x22c73e0, count=count@entry=9223372036854775807, isTopLevel=isTopLevel@entry=true, run_once=run_once@entry=true, dest=dest@entry=0x2348938, altdest=altdest@entry=0x2348938, 
    completionTag=0x7ffdc444f190 "") at pquery.c:765
#21 0x00000000007aee40 in exec_simple_query (query_string=0x22617b0 "explain analyze select a, b, sum(c) from t2 group by 1, 2;") at postgres.c:1227
#22 0x00000000007b0903 in PostgresMain (argc=<optimized out>, argv=argv@entry=0x228f3d8, dbname=<optimized out>, username=<optimized out>) at postgres.c:4291
#23 0x000000000072f51e in BackendRun (port=0x2287140, port=0x2287140) at postmaster.c:4498
#24 BackendStartup (port=0x2287140) at postmaster.c:4189
#25 ServerLoop () at postmaster.c:1727
#26 0x0000000000730317 in PostmasterMain (argc=argc@entry=3, argv=argv@entry=0x225b390) at postmaster.c:1400
#27 0x000000000047e191 in main (argc=3, argv=0x225b390) at main.c:210