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Re: JVM crash when select count(*) on large table through JDBC

From: Dave Cramer <pg(at)fastcrypt(dot)com>
To: Andres Olarte <olarte(dot)andres(at)gmail(dot)com>
Cc: "Kris Jurka" <books(at)ejurka(dot)com>, "Kai Ruhl" <k(dot)ruhl(at)etamax(dot)de>, pgsql-jdbc(at)postgresql(dot)org
Subject: Re: JVM crash when select count(*) on large table through JDBC
Date: 2008-02-22 21:13:18
Message-ID: 6CA15016-F105-4963-B9B2-3462EA2B3B53@fastcrypt.com (view raw or flat)
Thread:
Lists: pgsql-jdbc
As Kris said and I said. If your jvm crashes it's a jvm problem.

I know people that have queries that take 20 minutes or more...

Dave
On 22-Feb-08, at 3:39 PM, Andres Olarte wrote:

> I know it's the same to count 1 o 20M rows, but it takes much longer
> to count 20M.  I really don't know much about the internal of the
> driver, but maybe some kind of time out?
>
> On Fri, Feb 22, 2008 at 2:33 PM, Kris Jurka <books(at)ejurka(dot)com> wrote:
>>
>> On Fri, 22 Feb 2008, Andres Olarte wrote:
>>
>>> Just did a quick test with synthetic data (20M rows 3 columns:  
>>> serial,
>>> timestamp, and text).  And it worked ok both on Java (with driver
>>> postgresql-8.1-407.jdbc3.jar)  and PgAdmin.
>>>
>>> Perhaps you could try to build a test case to expose the problem?
>>
>> From a client perspective, select count(*) should be the same no  
>> matter
>> how many rows there are and what types of columns are in the table,  
>> so a
>> test case won't be helpful.  If the JVM is just up and dying,  
>> that's the
>> JVM's fault not a pg issue.
>>
>> Kris Jurka
>>
>
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