ORA-01467：排序键太长

Question

我有以下选择产生错误。 [1]：ORA-01467：排序键太长 这来自旧的代码块，我无法从表中删除列。还有其他方法可以解决此错误吗？

SELECT distinct c_id,
   LTRIM(MAX(SYS_CONNECT_BY_PATH(uW,','))
   KEEP (DENSE_RANK LAST ORDER BY curr),',') AS uW
FROM   (SELECT distinct c_id,
           uW,
           ROW_NUMBER() OVER (PARTITION BY c_id ORDER BY uW) AS curr,
           ROW_NUMBER() OVER (PARTITION BY c_id ORDER BY uW) -1 AS prev
    FROM   tmp2)
GROUP BY c_id
CONNECT BY prev = PRIOR curr AND c_id = PRIOR c_id
START WITH curr = 1;

Answer 1

根据Oracle文档，排序/分组列的总长度+一些开销不得超过块大小（通常为8K）。使用较新的Oracle版本，例如charset AL32UTF8，tmp2.uW ortmp2.c_id的列大小可能会超过4000个字符，并且会超过8000个字节。