From: Robert Klemme <bob.news@...>
Date: 2005-09-10T00:06:30+09:00
Subject: Re: general performance question

Brian Le Roy wrote:
> Thanks Robert!
>
> I think I found the culprit.
>
> With 20 records in the result:
> total ms/call
> 12300.00  Mysql::Result#each
>
> With 1 record in the result:
> total ms/call
> 600.00  Mysql::Result#each
>
> The query behind this result set is indexed properly.  Not sure why
> this takes so long - shouldn't it be as fast as a regular array.each
> call?

Unlikely, as the data has to be fetched over the network (even if it's
local).  Even with prefetching etc. this is slower than iterating an array
in mem.  Also, the accumulated time of each depends on the complexity of
the operation in the block - that's sometimes overlooked.  Note that #each
is called only once per iteration but the block is invoked multiple times.

Kind regards

    robert