Nested tables are implemented as normlised tables
with a meaningless key combined with a hidden
unique constraint on the parent table, so it's all
overhead and no (physical) benefit over doing it
the relational way.
--
Jonathan Lewis
Yet another Oracle-related web site: http://www.jlcomp.demon.co.uk
Practical Oracle 8i: Building Efficient Databases
Publishers: Addison-Wesley
See a first review at:
http://www.ixora.com.au/resources/index.htm#practical_8i
More reviews at: http://www.jlcomp.demon.co.uk/book_rev.html
gnn_gnn wrote in message <93ebi5$t56$1_at_nntp9.atl.mindspring.net>...
>Hi:
>
>I have been looking at the documentation on defining types, objects, nested
>tables, etc. in Oracle 8i and have a basic question on the topic as a NB.
>Some of these things look very interesting, like points, lines, etc. But
>how does the query speed stack up? For example, if I wanted a list of
>people and all of their credit card transactions for a month (or several
>months) and wanted to do queries like "show all the people, and the
>transactions who spent more than $200 on clothes in the month of december".
>Would I be better off using something like nested tables (performance-wise)
>or breaking out the credit card transactions into a separate table with a
>foreign key back to the user table? What are the pros and cons of each
>method?
>
>Thanks,
> Mike
>
>
>
Received on Tue Jan 09 2001 - 13:21:35 CST
