From: Robert Klemme <bob.news@...>
Date: 2005-11-29T17:22:29+09:00
Subject: Re: building ruby for speed: wise or otherwise?

Hugh Sasse wrote:
> On Tue, 29 Nov 2005, Robert Klemme wrote:
>
>> If Hugh is using ActiveRecord intensively with a database then it's
>> most likely that he'll see no positiv performance effect from
>> compiling it with more aggressive optimization.
>>
>> In fact it's likely that careful optimization on the database side
>> will yield better results.  This can be as easy as creating some
>> indexes - but might be much more complicated - depending on the
>> bottleneck.  (Often it's IO and this might have several reasons,
>> from sub optimal execution plans to slow disks / controllers.)
>>
> At the moment my script to populate the tables is taking about an
> hour.  Anyway it's mostly ruby I think, because it spends most of
> the time setting up the arrays before it populates the db with them.

How did you measure that?

> Besides that, I'm fairly new to database work, so I'm trying to
> optimize what I know about before I start fiddling with the db.

Um, although I can understand your waryness with regard to the unknown -
you may completely waste your time.  IMHO you should first determine the
cause of the slowness and then find a solution.  If you optimize something
that just takes 10% of the whole running time you'll never seen an
improvement of more than 10%...

Another option to get masses of data into a database is to use some form
of bulk insert / bulk load.  Depending on your database there are probably
several options.

> Slow disks/controllers (+ lots of users) could be a factor, the
> machine is 5.5 years old.

Could be.  If possible spend it at least more mem.

Kind regards

    robert