Re: double linked list

--CELKO-- wrote:

> >> Being a novice in SQL and after doing just a couple of days of
> research on that matter ... <<
>
> Another boss who will not pay for training :0!!
>
> >> I got the impression that SQL hasn't yet evolved to that point to
> provide simple to use keywords for these kind of problems. <<
>
> SQL is a set oriented language, not a procedural language. You have
> to learn to model data in terms of sets and not sequences to use it.
>
> >> Oracle 9i seems to have been progressed over 8i in this regard. <<
>
> Actually, Oracle is a horrible product and their extensions are flaws
> that lock the code into a particular underlying sequential physical
> implementation with sorting and cursors, no parallelism, etc.
>
> >> Currently I figure to use
>
> SELECT cs, cb, level
> FROM link_t
> START WITH cb
> IN (SELECT cb
> FROM link_t
> WHERE cs = 'A')
> CONNECT BY PRIOR cb = cs;
>
> that will return a tree containing all paths with the root as the
> common starting point. <<
>
> It returns a sequential file that represents a table and that
> represernation depends on the order of the records (they are no
> longer rows in a table).
>
> >> I would load this structure into a middle tier and apply some sort
> of commonly used tree traversial algorithm to it to search for nodes
> and endpoints of interest. <<
>
> You can do all of those searches in the Nested Sets model with a
> single query, no middle ware and they will run 10 to 100 times faster
> for large trees.
>
> I have a book on trees in SQL that will be published later this year
> that you might want to buy.

I'll not take issue with you with respect to your field of expertise. But to say Oracle is a horrible product presumes two things: first that you are being objective with respect to Oracle in comparison with other products, and second that you have sufficient expertise with the product from which to render that opinion.

If I am incorrect I will gladly stand corrected. But based on my knowledge of what you have been doing for the last few years ... I have my doubts about both. I have worked with databases from Teradata to Oracle to DB2 and most of the rest of the field. And I see nothing in Oracle that isn't at least the equal to the other major RDBMS implementations including the one in which you do your work.

Daniel Morgan Received on Sat Feb 01 2003 - 22:36:16 CET