sql - ORA-30009 : Not enough memory for CONNECT BY operation/ORA-01788: CONNECT BY clause required in this query block

Question

这里是 Oracle 新手 - 我正在尝试运行插入语句来生成大量数据。

1. 原始查询是这样的:

INSERT INTO HR.fastData (ID) 
SELECT 1 + (Level -1) * 1 
FROM dual connect by Level < 100000000;

收到的第一个错误:

ORA-30009: Not enough memory for CONNECT BY operation

我关注了the guidance provided here

修改后的查询:

INSERT INTO HR.fastData (ID) 
SELECT 1 + (Level -1) * 1 
FROM
    (select level from dual connect by Level < 10000),
    (select level from dual connect by Level < 10000);

我收到的下一个错误:

ORA-01788: CONNECT BY clause required in this query block

修改后的查询现在如下所示:

INSERT INTO HR.fastData (ID) 
SELECT 1 + (Level -1) * 1 
FROM DUAL CONNECT BY 
     (select Level from dual connect by Level < 10000),
     (select Level from dual connect by level < 10000);

在多次尝试不同的查询变体后，我无法正确执行此操作。我是否正确使用/放置了 CONNECT BY 语句？将不胜感激任何指导。

谢谢!

Answer 1

您想要的查询似乎是

SELECT ((lvl1-1)*10) + (lvl2-1) + 1 as ID
  FROM (select level as lvl1 from dual connect by Level <= 10000)
  CROSS JOIN (select level as lvl2 from dual connect by Level <= 10000);

我不能保证您的系统可以一次性生成所有这些数字，但原则上这是可行的。 Here's a db<>fiddle这表明当每个子查询限制为 10 个级别、总共生成 100 行时，此查询有效。