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Old February 25th, 2010, 05:51 AM posted to microsoft.public.access.tablesdbdesign
Dennis
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Posts: 1,222
Default Restated: "Fields are expensive, records are cheap"

Hi,

First let me apolozie for the empty question below. I hit the Post button
my mistake and it posted a blank question. Sorry.

Hi,

I am restating my question because based upon the responses I receive I
obviously stated my question incorrectly. So please let me try again.
Hopefully I will be a bit more sucessful this time around.


In a previous question, I stated that I added 30 fields the membership table
(one of many in the system). The initial implementation was SO successful,
that the user requested quite a few enhancements resulting in the in a HUGE
increase in the scope of the original project. These changes resulted in
the addition of 30 new fields to the membership table.

The last time people responded to my question, they were concerned about the
whether or not these were normalized fields. Please let me state that the
row has been normalized to 3rd normal form and these fields are NOT
re-occurring fields.

One MVP who responded to my original question stated "Fields are expensive,
records are cheap".

Maybe I am misinterpreting his comment. But to me this means that it is
better to have smaller row in multiple linked tables than it is to have one
large row that contains all of the normalized data. (IE – it is better to
split a large normalize row in a single table into multiple rows in multiple
tables). I hope I explained that the right way.


My question pertains to the difference in the disk access time it takes to
retrieve one record from the disk over a network versus retrieving multiple
records versus the overhead involved in Access parsing a lot of fields out of
a large row or parsing the same number of fields from multiple smaller rows.


I've always been taught the exact opposite - that "Fields are cheap, records
are expensive" since going to disk is so SLOW versus accessing data in
memory.

Is there something different about Access where the statement "Fields are
expense, records are cheap" is true? I'm using Access on local machine where
the front and backs end reside on the same machine as well as having multiple
front ends on each client's machine tied into the back end which resides on a
file server over a cat 5 hardwired Ethernet network.

My question is strictly concerning the data access time of multiple row over
the network versus Access’ overhead of extracting data from multiple small
rows versus one large row. And we are assuming a 3rd normal form database
design.

And it may well be that I am totally misinterpreting the “Fields are
expensive, records are cheap” comment.

Thank you for your comments.



Dennis