Re: usage for 'with recursive'?

hubert depesz lubaczewski wrote:
> On 3/1/07, Kenneth Downs <ken@secdat.com> wrote:
>> Better?  I think perhaps different.  There is materialized path, which
>> requires a very problematic unlimited-length column to hold the path,
>> and there is upper/lower bounds, which again requires client-side
>> row-by-row processing.  Both have the unpleasant problem that changes to
>> one row may affect many others.
>
> there are also other approaches.
> i know that they are not that well known, but there are, and they
> allow many things to be done with very simple queries.
> i use a solution which basically allows me to query every kind of
> tree-structure data without loops or recursion. drawbacks are 2 and
> are very limited:
> 1. it uses some triggers
> 2. it has some (slight in my opinion) overhead.

I see you've moved the client-side code to the server, which is a Good
Thing in my book.

The overhead would be proportional to the number of rows that have to be
looked at when a new row goes in.

This reminds me of another advantage of the WITH RECURSIVE, which is
that it pushes to overhead to SELECT, with no associated write-time
overheads.


--
Kenneth Downs
Secure Data Software, Inc.
www.secdat.com / www.andromeda-project.org
Office: 631-689-7200   Cell: 631-379-0010

::Think you may have a problem with programming? Ask yourself this
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