Re: Postgres refusing to use >1 core - Mailing list pgsql-performance

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Subject Re: Postgres refusing to use >1 core
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Msg-id 201105111953.060147@ms14.lnh.mail.rcn.net
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In response to Re: Postgres refusing to use >1 core  (Shaun Thomas <sthomas@peak6.com>)
Responses Re: Postgres refusing to use >1 core  (Scott Marlowe <scott.marlowe@gmail.com>)
Re: Postgres refusing to use >1 core  (Shaun Thomas <sthomas@peak6.com>)
List pgsql-performance
---- Original message ----
>Date: Wed, 11 May 2011 11:04:49 -0500
>From: pgsql-performance-owner@postgresql.org (on behalf of Shaun Thomas <sthomas@peak6.com>)
>Subject: Re: [PERFORM] Postgres refusing to use >1 core
>To: Scott Marlowe <scott.marlowe@gmail.com>
>Cc: Craig Ringer <craig@postnewspapers.com.au>,Aren Cambre <aren@arencambre.com>,<pgsql-performance@postgresql.org>
>
>On 05/10/2011 11:26 PM, Scott Marlowe wrote:
>
>> I.e. don't grab 1,000 rows and work on them on the client side and
>> then insert data, do the data mangling in the query in the database.
>> My experience has been that moving things like this into the database
>> can result in performance gains of several factors, taking hour long
>> processes and making them run in minutes.
>
>This is a problem I encounter constantly wherever I go. Programmer
>selects millions of rows from giant table. Programmer loops through
>results one by one doing some magic on them. Programmer submits queries
>back to the database. Even in batches, that's going to take ages.
>
>Databases are beasts at set-based operations. If the programmer can
>build a temp table of any kind and load that, they can turn their
>update/insert/whatever into a simple JOIN that runs several orders of
>magnitude faster. Going the route of parallelism will probably work too,
>but I doubt it's the right solution in this case.
>
>When there are tables with millions of rows involved, processing 111 per
>second is a bug. Even with ten perfectly balanced threads, 30 hours only
>becomes three. On decent hardware, you can probably drop, reload, and
>index the entire table faster than that.
>
>--
>Shaun Thomas
>OptionsHouse | 141 W. Jackson Blvd. | Suite 800 | Chicago IL, 60604
>312-676-8870
>sthomas@peak6.com
>
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So, the $64 question:  how did you find an engagement where, to bend Shakespeare, "first thing we do, is kill all the
coders"isn't required?  This RBAR mentality, abetted by xml/NoSql/xBase, is utterly pervasive.  They absolutely refuse
tolearn anything different from the COBOL/VSAM messes of their grandfathers; well modulo syntax, of course.  The mere
suggestion,in my experience, that doing things faster with fewer lines of code/statements in the engine is met with
overthostility. 

Regards,
Robert

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