[PLUG] SQL DB structure question

[Rich Shepard]

On Sat, 15 Jun 2002, J Henshaw wrote:

> Don't they have books for this stuff?

  Yes, there are many textbooks out on database design and structure.

  An (old) book that I found very useful is McFadden & Hoffer's "Database
Management", Third Ed. (1991). I'm sure the more current books are even
better.

> > Assume that all tables in DB have the same number of columns e.g.10.
> > What is better for DB performance to have few of bigger/longer tables
> > or lot of smaller/shorter tables?

  Unfortunately, this is the wrong question. The focus of this thread
appears to be optimizing disk reads (and, perhaps, writes) to the physical
file structure on disk. Every database book I've read, and all the
discussions in which I've been involved in the past couple of decades, focus
on optimizing the logical structure of the database; i.e., normalizing to
third or fourth Normal Form, and when to violate those rules.

  Physical -- hardware -- access will vary with the components installed.
Performance tuning is almost always a function of database logical structure
because that determines how data are accessed or written. Most folks select
the dbms backend based on features they require or want and allow that
backend to control the writing and reading of data on and off the hard
drives. The dbms programmer can then focus on the system schema and writing
the most efficient SQL statements to query the data and maintain as many of
Cobb's 12 rules for data integrity as are implemented in the software.

Rich