Rails - Sep 2005 - keeping (long) records of things: best practice?

I''m trying to get the design right for a rails based loans system.
Rails has logging. but I want to keep a record of past loans per
{person, item} (for as long as this is deemed legitimate), rather
than just keep a record of what they have on loan now.  This would
be so if they have to borrow specialised kit we will know they have
had it before (so have been trained), and we can to keep a
"biography" of the kit [how many times it has been dropped :-), and
so on].  Keeping this in tables would allow it to be consulted
relatively easily, as opposed to logfiles for which we have to write
the parsers, which would not be so fast.  With approximatley 1000
users, and loans going in and out every day for a year at least, is
it sensible to just shovel this information into a table?

I''m using MySQL with Apache, on Solaris, but I realise this is a
string-length question.  So, do people just consult the logfiles or use
a database for this sort of thing?  Do they do something else
altogether?  I''ve not done much with databases before, so am
probably rather clueless about best practice and lack knowledge of
the right places to look for advice on this, so pardon this (daft?)
question.  How big can tables get before performance gets poor?
Yes, it depends on machine speed, desired response time, and
probably what is in the table, but there may be order of magnitude
rules of thumb here....

         Thank you,
         Hugh

In article
<Pine.GSO.4.63.0509261701260.18250-PnKidU7MZKzcl/KssxhpDpUoLBXZAXmj@public.gmane.org>,
hgs-C9usXPTk/FFaa/9Udqfwiw@public.gmane.org says...
> How big can tables get before performance gets poor?
> Yes, it depends on machine speed, desired response time, and
> probably what is in the table, but there may be order of magnitude
> rules of thumb here....
It depends SO much on those factors (as well as the most important 
factor, the database engine) that I''m not sure there''s an
answer any
more specific than to the question "how long is a piece of string, in 
general"?

To give you some idea, every AOL member''s mailbox (the list of their e-
mail) is stored in a single SQL table - read, unread and outbound (until 
recently, there were no folders, but IIRC the folder-ID is just an 
indexed field in the table).  For some system mailboxes, this can tally 
in the tens of thousands of messages.  It''s never been a performance 
problem; in fact, it is significantly faster than the flat-file, single-
record blob-type storage previously used for the list.  But, again,
it''s
hard to compare, because the blob was on a slow filesystem on a slow 
minicomputer, and the database is on a minicomputer that actually 
implements SQL at the disk-controller level for speed.

A lot depends on whether you can pull all the data in one query or not.  
If you can, most databases can efficiently perform most queries most of 
the time.  If you''re making thousands of queries, one for each row,
then
yeah, you''ll run into problems.  That''s why "eager
loading of
associations" was such a win for Rails.

-- 
Jay Levitt                | 
Wellesley, MA             | I feel calm.  I feel ready.  I can only
Faster: jay at jay dot fm | conclude that''s because I don''t
have a
http://www.jay.fm         | full grasp of the situation. - Mark Adler