aligputf8=# explain analyze select sum(col1),sum(col2),sum(col3),sum(col4),sum(col5),sum(col6),sum(col7),sum(col8),sum(col9),   
max(col1),max(col2),max(col3),max(col4),max(col5),max(col6),max(col7),max(col8),max(col9), 
avg(col1),avg(col2),avg(col3),avg(col4),avg(col5),avg(col6),avg(col7),avg(col8),avg(col9) from test_group group by id;
                                             QUERY PLAN                                             
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 HashAggregate  (cost=15225.85..29783.06 rows=108256 width=66)
   Group By: id
   Rows out:  100000 rows with 722 ms to first row, 1367 ms to end, start offset by 0.125 ms.
   Executor memory:  32536K bytes.
   Work_mem used:  32001K bytes.
   Work_mem wanted: 106876K bytes to lessen workfile I/O.
   100000 groups total in 32 batches; 1 overflows; 100000 spill groups.
   Hash chain length 1.8 avg, 20 max, using 74100 of 135168 buckets.
   ->  Seq Scan on test_group  (cost=0.00..1480.56 rows=108256 width=66)
         Rows out:  100000 rows with 0.016 ms to first row, 51 ms to end, start offset by 0.142 ms.
 Slice statistics:
   (slice0)  * Executor memory: 32697K bytes.  Work_mem: 32001K bytes max, 106876K bytes wanted.
 Settings:  enable_groupagg=off; enable_hashagg=on; enable_seqscan=off; work_mem=32000kB
 Total runtime: 1391.138 ms
(14 rows)