我正尝试在Oracle中执行以下查询:
SELECT DISTINCT
t4.s_studentreference "Student ID",
t3.p_surname "Surname",
t3.p_forenames "Forenames",
t1.m_reference "Course",
t2.e_name "Enrolment Name"
FROM student t4,
person t3,
enrolment t2,
course t1
WHERE t4.s_id(+) =t3.p_id
AND (t2.e_student=t3.p_id)
AND (t2.e_course =t1.m_id)
AND (t1.m_reference LIKE 'LL563%15')
OR (t1.m_reference LIKE 'LL562%15')
OR (t1.m_reference LIKE 'LL563%16')
OR (t1.m_reference LIKE 'LL562%16')但是,我得到了下面的错误:
ORA-01652: unable to extend temp segment by 128 in tablespace TEMP
01652. 00000 - "unable to extend temp segment by %s in tablespace %s"
*Cause: Failed to allocate an extent of the required number of blocks for
a temporary segment in the tablespace indicated.
*Action: Use ALTER TABLESPACE ADD DATAFILE statement to add one or more
files to the tablespace indicated.我使用下面的查询来查找临时段空间:
select inst_id, tablespace_name, total_blocks, used_blocks, free_blocks
from gv$sort_segment;提供:
INST_ID, TABLESPACE_NAME, TOTAL_BLOCKS, USED_BLOCKS, FREE_BLOCKS
1 TEMP 3199872 15360 3184512你知道怎么解决吗?
谢谢,阿鲁娜
发布于 2017-02-13 22:59:25
虽然解决这个问题的标准答案是让DBA扩展临时表空间,但我认为问题出在您的查询中。
具体地说,就是您编写WHERE子句谓词的方式。我怀疑前三个谓词是您的联接谓词,后四个谓词是为了限制正在联接的course表中的行。
然而,发生的情况是,前四个谓词是首先计算的(因为AND优先于OR),我怀疑这会导致您的连接出现一些问题-可能是一些意外的交叉连接,这可能是意外地炸毁您的临时表空间的原因。
为了防止这种情况发生,您有两种可能的解决方案:
1.在正确的位置使用括号来阐明您的AND/OR逻辑:
SELECT DISTINCT
t4.s_studentreference "Student ID",
t3.p_surname "Surname",
t3.p_forenames "Forenames",
t1.m_reference "Course",
t2.e_name "Enrolment Name"
FROM student t4,
person t3,
enrolment t2,
course t1
WHERE t4.s_id(+) = t3.p_id
AND t2.e_student = t3.p_id
AND t2.e_course = t1.m_id
AND (t1.m_reference LIKE 'LL563%15'
OR t1.m_reference LIKE 'LL562%15'
OR t1.m_reference LIKE 'LL563%16'
OR t1.m_reference LIKE 'LL562%16');上面的语句将所有OR语句组合在一起,然后将它们与其余谓词进行and运算。
2.使用ANSI连接语法并将搜索谓词从连接谓词中分离出来:
SELECT DISTINCT
t4.s_studentreference "Student ID",
t3.p_surname "Surname",
t3.p_forenames "Forenames",
t1.m_reference "Course",
t2.e_name "Enrolment Name"
FROM student t4,
RIGHT OUTER JOIN person t3 ON t4.s_id = t3.p_id
INNER JOIN enrolment t2 ON t3.p_id = t2.e_student
INNER JOIN course t1 ON t2.e_course = t1.m_id
WHERE t1.m_reference LIKE 'LL563%15'
OR t1.m_reference LIKE 'LL562%15'
OR t1.m_reference LIKE 'LL563%16'
OR t1.m_reference LIKE 'LL562%16';当然,当您在where子句中混合使用and和Of时,后者并不排除在正确的位置使用括号...
选项2将是我首选的解决方案-- ANSI join语法是目前编写SQL时的发展方向。
https://stackoverflow.com/questions/42206369
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