摘要:

执行完Q18的语句，内存使用了135GB，分析究竟为何使用这么多

SQL语句：

select
	c_name,
	c_custkey,
	o_orderkey,
	o_orderdate,
	o_totalprice,
	sum(l_quantity)
from
	customer,
	orders,
	lineitem
where
	o_orderkey in (
		select
			l_orderkey
		from
			lineitem
		group by
			l_orderkey having
				sum(l_quantity) > 300
	)
	and c_custkey = o_custkey
	and o_orderkey = l_orderkey
group by
	c_name,
	c_custkey,
	o_orderkey,
	o_orderdate,
	o_totalprice
order by
	o_totalprice desc,
	o_orderdate
limit 100;

火焰图:

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