[LRUG] Request for assistance with Rails performance oddity

[Michael Pavling]

On 29 October 2010 20:09, John Winters <john at sinodun.org.uk> wrote:
> When I first run the script with empty database tables it runs at a
> perfectly satisfactory rate.  Loading a total of 105171 records takes
> 1662s, or a rate of 63.3 records/second.  Further, it doesn't slow down
> as it loads - the rate of loading is the same when there are 100,000
> records loaded as it was at the beginning.
>
> If however I let the script stop and then start it again to load a
> second batch it runs far more slowly.  A small further batch of 1384
> records takes 584s, or about 2.4 records/second.

What happens if you load the second batch first? Do they load at the
same, slow speed if the DB starts off empty?

Any chance you can post or link to some (sanitized/anonymised) code
and a source examples?