Abnormally low performance on INSERTS?

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Hi all

=20

We are conducting a database test here in Skellefte=E5, comparing MySQL,
Access and Postgre in a lab assignment.

The problem we have with MySQL database is that INSERT-performance is
abnormally slow on some computers and as fast as expected on others. For
instance, if I run the test application on my computer at home the =
complete
test sequence would take about 6 minutes. It includes ~250 000 INSERTS, =
so
no extreme amount. If I would run the same test with my laptop, I =
estimate
the time it would take to about 2=BD hours... and the performance hit is =
more
or less completely related to INSERTS.

=20

The problem is replicated on numerous computers and all of them are =
using
standard settings and InnoDB. But the same settings are used on those
computers were it works as expected... and if it was a bug related to =
InnoDB
with maybe 50% of all computers affected, why isn't it documented with a
solution?

=20

To simplify it, you can say that the performance delta on INSERTs are =
1:23
between two reasonably equal computers. Other databases (Access and =
Postgre)
might have a delta of 1:1.2 or something similar at worst.

=20

WinXP OS with SP2, DOT.NET and tested with both C# and C++, both MySQL =
4.x
and 5.0.12. MyODBC 3.51.

=20

INSERTs are being conducted in three different tables, no huge data =
sizes
and the tables are being mixed while inserting data.

If changing engine to MyISAM would be an option, the problem would be
solved=85 performance is then as expected. But since MyISAM lacks too =
much
features, it would be to compare apples with bananas.

=20

We would appreciate any tips regarding this matter, if you have any
questions regarding our MySQL settings you can simply check the =
defaults=85 no
tweaks or anything, shouldn=92t be necessary for this kind of test.

=20

Regards Sture Eklund

=20


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Re: Abnormally low performance on INSERTS?

Hi,

Sture Eklund wrote:
> test sequence would take about 6 minutes. It includes ~250 000 INSERTS, so
> no extreme amount. If I would run the same test with my laptop, I estimate
> the time it would take to about 2½ hours... and the performance hit is more
> or less completely related to INSERTS.
>
when it comes to laptops, the speed of hard disks is real slow.

What is the amount of RAM used in the machines. Sometimes, a lot of RAM
can compensate this.

I have also a huge difference between normal machine an notebook. But
this difference is roughly the same for all programs with intense disk
access.

So, RAM could help in your case.

I never used MySQL on a notebook.

Erich

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Re: Abnormally low performance on INSERTS?

Hi,=20

I use MySQL in my Laptop, specially for devel, but sometimes with intense=
=20
imports (as when I was writing the processor for my stats software -=20
http://stats.camelot.co.pt), that was written with a bigger portal logs, an=
d=20
I had no abnormal performance issues, but I have 1GB of RAM, of which most =
of=20
the time 512MB are buffers.

I think that this can help a lot.

themage

On Thursday 20 October 2005 09:26, Erich Dollansky wrote:
> Hi,
>
> Sture Eklund wrote:
> > test sequence would take about 6 minutes. It includes ~250 000 INSERTS,
> > so no extreme amount. If I would run the same test with my laptop, I
> > estimate the time it would take to about 2=BD hours... and the performa=
nce
> > hit is more or less completely related to INSERTS.
>
> when it comes to laptops, the speed of hard disks is real slow.
>
> What is the amount of RAM used in the machines. Sometimes, a lot of RAM
> can compensate this.
>
> I have also a huge difference between normal machine an notebook. But
> this difference is roughly the same for all programs with intense disk
> access.
>
> So, RAM could help in your case.
>
> I never used MySQL on a notebook.
>
> Erich

=2D-=20
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