Question

我有一张约有1亿行的表格。必须使用BETWEEN运算符。我看到查询运行速度很慢。

我在t.name上的交易者表1上添加了2个索引，第二个索引是t.amount和t.price。

查询执行速度很慢。在使用BETWEEN运算符时，对价格和金额进行索引是否有帮助。另外，我该如何优化呢？

select t.trader_id, t.name, t.city, t.state 
from trader t where exists 
( 
SELECT null 
FROM city_present p,city_state c 
WHERE p.name = 'TEST_TEST'
AND c.city = p.city
AND c.state = p.state
AND t.city = c.city 
AND t.state = c.state 
AND t.price IS NOT NULL 
AND t.price between (25.00000 , 58.000000) 
AND t.amount IS NOT NULL 
AND t.amount BETWEEN (-2500.0000 , 2800.000) 
) 
AND t.name = 'john test' 
AND t.is_valid= 1

Answer 1

选择性是优化绩效的关键 - 在city_present.name为'TEST_TEST'的城市/州中，您可能拥有名为'john test'的交易员，其中is_valid = 1，而且价格介于25和58之间数量介于-2500和2800之间。

因此，我建议在交易者表上设置索引，名称，城市，州和is_valid（按此顺序），然后尝试以下查询：

SELECT t.trader_id, t.name, t.city, t.state 
FROM trader t
JOIN (select distinct p.city, p.state
      from city_present p
      JOIN city_state s
        ON s.city  = p.city AND s.state = p.state 
      WHERE p.name = 'TEST_TEST') c
  ON t.city  = c.city AND t.state = c.state 
WHERE t.price between (25.00000 , 58.000000) 
  AND t.amount BETWEEN (-2500.0000 , 2800.000) 
  AND t.name = 'john test' 
  AND t.is_valid= 1

使用BETWEEN运算符进行Oracle查询性能

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