Jose, In addition to any advice you may receive from your post today, check out the PHP archives. I distinctly remember a discussion related to these models maybe a month back that may be of interest to you. Don't remember if it dealt with your specific concerns, but I'm pretty sure it dealt with the flexibility of application of the two models in different environments.
Happy hunting. Rich > -----Original Message----- > From: José Moreira [mailto:[EMAIL PROTECTED]] > Sent: Thursday, December 19, 2002 11:45 AM > To: Php-Db (Correio electrónico) > Subject: [PHP-DB] trees in MySQL > > > hello im implementing a portal and im choosing between the > 'Nested Set' and > 'Adjacency Lists tree' models. > <http://users.starpower.net/rjhalljr/Serve/MySQL/traer.html> > > > im perfectly aware of the 'Adjacency Lists tree' model how-to and I am > studying the 'Nested Set', example follows : > > CREATE TABLE LanguageTree ( > > Language VARCHAR(255) PRIMARY KEY > , Parent VARCHAR(255) > , Lft LONG > , Rgt LONG > , INDEX idxLft (Lft) > , INDEX idxRgt (Rgt) > ) Comment = "Related languages"; > > > A[1 12] > / \ > / \ > B[2 3] C[4 11] > / \ > / \ > D[5 8] F[9 10] > | > E[6 7] > > > my doubt is that if i want to insert a new node, for example > 'G' under 'A' > > A[1 12] > / | \ > / \ > B[2 3] G[] C[4 11] > / \ > / \ > D[5 8] F[9 10] > | > E[6 7] > > > i have? to update almost every left,righ fields after that > node, resulting > in a website performance downgrade .... > > > help? even if thjats the only way, how can i do it? perhaps > im getting it > wrong ... > > > best regards > > > José Moreira > TEGOPI S.A. > http://www.tegopi.pt > > > > > > > > > > -- > PHP Database Mailing List (http://www.php.net/) > To unsubscribe, visit: http://www.php.net/unsub.php > -- PHP Database Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
