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PUBLIC MARKS from ogrisel with tags database & modeling

15 February 2007 01:00 Trees in SQL: Nested Sets and Materialized Path

by 1 other (via)
Relational databases are universally conceived of as an advance over their predecessors network and hierarchical models. Superior in every querying respect, they turned out to be surprisingly incomplete when modeling transitive dependencies. Almost every couple of months a question about how to model a tree in the database pops up at the comp.database.theory newsgroup. In this article I'll investigate two out of four well known approaches to accomplishing this and show a connection between them. We'll discover a new method that could be considered as a "mix-in" between materialized path and nested sets.

15 February 2007 00:00

Making a tree with "millions and millions" of dynamic nodes

First mail of a thread on the postgresql mailing list dealing of various ways to implement a tree structure with PostgreSQL.

Representing Trees in a relational DB

This document describes an approach for handling hierarchical data in a relational database.

14 February 2007 21:00

Denormalization - Wikipedia, the free encyclopedia

Denormalization is the process of attempting to optimize the performance of a database by adding redundant data. It is sometimes necessary because current DBMSs implement the relational model poorly. A true relational DBMS would allow for a fully normalized database at the logical level, while providing physical storage of data that is tuned for high performance.


Heuristics for denormalizing relational database tables are examined with an objective of improving processing performance for data insertions, deletions and selection. Client-server applications necessitate consideration of denormalized database schemas as a means of achieving good system performance where the client-server interface is graphical (GUI) and the network capacity is limited by the network channel.

ogrisel's TAGS related to tag database

denormalization +   documentation +   export +   hierarchical +   knowledge extraction +   memory +   modeling +   performance +   postgresql +   rdf +   semantic web +   sql +   tree +   tuning +   web of data +