锁总数超过锁表大小

Error code 1206: The number of locks exceeds the lock table size.

有问题的查询是:

create temporary table SkusBought(
customerNum int(11),
sku int(11),
typedesc char(25),
key `customerNum` (customerNum)
)ENGINE=InnoDB DEFAULT CHARSET=latin1;
insert into skusBought
select t1.* from
    (select customer, sku, typedesc from transactiondatatransit
    where (cat = 150 or cat = 151)
    AND daysfrom07jan1 > 731
group by customer, sku
union
select customer, sku, typedesc from transactiondatadelaware
    where (cat = 150 or cat = 151)
    AND daysfrom07jan1 > 731
group by customer, sku
union
select customer, sku, typedesc from transactiondataprestige
    where (cat = 150 or cat = 151)
    AND daysfrom07jan1 > 731
group by customer, sku) t1
join
(select customernum from topThreetransit group by customernum) t2
on t1.customer = t2.customernum;

我读过更改配置文件以增加缓冲池大小会有所帮助，但这没有任何作用.解决此问题的方法是临时解决方法还是永久解决方法?