Question

我的postgres因长时间查询而崩溃。它在Debian 7 64bit和postgresql-9.3.2上。我使用所有默认配置。有人可以提出它可能存在什么问题吗？谢谢。

 --part1:
 SELECT r1.f2 as b, r1.e as l 
 FROM r r8,r r7,r r6,r r5,r r4,r r3,r r2,r r1
 WHERE
 r1.f2=r2.f1 AND 
 r1.f2=r3.f1 AND 
 r1.f2=r4.f1 AND 
 r1.f1=r5.f2 AND 
 r1.f1=r8.f1 AND 
 r2.f1=r3.f1 AND 
 r2.f1=r4.f1 AND
 r2.f2=r6.f2 AND 
 r2.f2=r7.f1 AND 
 r3.f1=r4.f1 AND 
 r3.f2=r7.f2 AND 
 r3.f2=r8.f2 AND 
 r4.f2=r5.f1 AND 
 r4.f2=r6.f1 AND 
 r5.f1=r6.f1 AND 
 r5.f2=r8.f1 AND 
 r6.f2=r7.f1 AND 
 r7.f2=r8.f2 AND 
 r1.d=1 AND
 r2.d=1 AND
 r3.d=2 AND
 r4.d=2 AND
 r5.d=2 AND
 r6.d=2 AND
 r7.d=2 AND
 r8.d=2
 -- part2
 group by r1.f2,r1.e
 having
 calc_empty_a() AND
 calc_empty_b();

在查询中，calc_empty_a（）只是空布尔函数（返回true），因此它们应该没有问题。

如果我在客户端运行查询，服务器崩溃。日志中没有任何有用的信息（请参阅帖子末尾的错误信息）。
如果我运行第1部分查询，则查询效果很好。
如果我第一次运行第1部分查询，那么我运行整个查询，它运行良好。
如果我改变查询，减少r数，例如，只有r1到r6 FROM表，用r8，r7删除谓词，但保留第2部分的GROUP BY和HAVING子句。查询仍然有效。
如果查询在HVING子句中有一个空函数，则查询也可以正常工作，但如果有两个函数则会崩溃。

以下查询效果很好

 SELECT r1.f2 as b, r1.f1 as a , r1.e as e
 FROM r r8,r r7,r r6,r r5,r r4,r r3,r r2,r r1
 WHERE
 r1.f2=r2.f1 AND 
 r1.f2=r3.f1 AND 
 r1.f2=r4.f1 AND 
 r1.f1=r5.f2 AND 
 r1.f1=r8.f1 AND 
 r2.f1=r3.f1 AND 
 r2.f1=r4.f1 AND
 r2.f2=r6.f2 AND 
 r2.f2=r7.f1 AND 
 r3.f1=r4.f1 AND 
 r3.f2=r7.f2 AND 
 r3.f2=r8.f2 AND 
 r4.f2=r5.f1 AND 
 r4.f2=r6.f1 AND 
 r5.f1=r6.f1 AND 
 r5.f2=r8.f1 AND 
 r6.f2=r7.f1 AND 
 r7.f2=r8.f2  
 group by r1.f2,r1.f1, r1.e
 having
 calc_empty_a() AND
 calc_empty_a();

我已将os设置为使用严格过度使用模式：

sysctl -w vm.overcommit_memory=2

错误信息：

在客户

 The connection to the server was lost. Attempting reset: Succeeded.

在服务器

LOG:  terminating any other active server processes
WARNING:  terminating connection because of crash of another server process
DETAIL:  The postmaster has commanded this server process to roll back the current transaction and exit, because another server process exited abnormally and possibly corrupted shared memory.
HINT:  In a moment you should be able to reconnect to the database and repeat your command.
WARNING:  terminating connection because of crash of another server process
DETAIL:  The postmaster has commanded this server process to roll back the current transaction and exit, because another server process exited abnormally and possibly corrupted shared memory.
HINT:  In a moment you should be able to reconnect to the database and repeat your command.
LOG:  all server processes terminated; reinitializing
LOG:  database system was interrupted; last known up at 2014-11-07 16:47:03 GMT
LOG:  database system was not properly shut down; automatic recovery in progress
LOG:  redo starts at 0/2126C98
LOG:  record with zero length at 0/21A9D98
LOG:  redo done at 0/21A9D68
LOG:  last completed transaction was at log time 2014-11-07 16:47:26.844406+00
LOG:  autovacuum launcher started
LOG:  database system is ready to accept connections

Postgres因长时间查询而崩溃

0 个答案: