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Re: [INTERFACES] JDBC Query performance

From: "Postgres mailing lists" <postgres(at)weblynk(dot)com>
To: <pgsql-interfaces(at)postgreSQL(dot)org>
Cc: "Peter Mount (Home)" <peter(at)retep(dot)org(dot)uk>
Subject: Re: [INTERFACES] JDBC Query performance
Date: 1999-03-23 06:51:26
Message-ID: 003b01be74f9$942eb400$64ba01cc@earthlink.net (view raw or flat)
Thread:
Lists: pgsql-interfaces
That's what's interesting about this to me. Using psql, piping the results
to a file, it is less than a second, and the CPU time goes to 50% idle. The
file that I piped to ends up about 3.5MB's. Jdbc is about 90 seconds, and 0%
idle. I've put trace statements in, so I'm pretty sure that to return from
the executeQuery(sql); method is about 90 seconds. If you can't reproduce
it, then maybe I could send you the table that I query, or maybe you could
send me a table that you query of similiar size (~1200 rows, 25 columns, no
indexes, most columns are varchar() or float8() ), that it performs well on.
Rich.


>Hmmm, this is interesting. Does the cpu time match when the same queries
>are run through PSQL?
>
>Peter
>
>--
>Peter T Mount, IT Section
>petermount(at)it(dot)maidstone(dot)gov(dot)uk
>Anything I write here are my own views, and cannot be taken as the
>official words of Maidstone Borough Council
>
>-----Original Message-----
>From: Postgres mailing lists [mailto:postgres(at)weblynk(dot)com]
>Sent: Sunday, March 21, 1999 7:11 PM
>To: pgsql-interfaces(at)postgreSQL(dot)org
>Subject: Re: [INTERFACES] JDBC Query performance
>
>
>>At 11:07 +0200 on 18/03/1999, Peter Mount wrote:
>>
>>
>>>
>>> The delay is because the driver currently retrieves the entire result
>>> into a Vector() before returning the ResultSet.
>>
>>Couldn't it also be because of Java's usage of network sockets compared
>to
>>psql's use of unix sockets?
>>
>You know, I also noticed that it is the postgres back-end process which
>is
>using all the CPU time during the query. Doesn't sound like Vector
>operations to me, which should cause the java process to eat all the CPU
>time.
>Rich.
>
>


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Subject: Re: [INTERFACES] PostGreSQL --> Oracle Convertor
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Subject: Re: [INTERFACES] JDBC Query performance

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