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News on "5 stars level"

Fast database stored tree traversal
Posted by pk on Sunday, September 14 2014 - 15:23:22
5 stars levelphp languageMySQL

The simplest way to store a tree structure into a database is obviously the table structure in which each record represents a node, and where a column is used to specify the key of the parent node.

This is by far the most convenient way for tree operation handling (insert, delete a node, etc.).
The tree traversal is very easy and is done with a simple recursive micro-function.

The downside to this advantage (and yes, it is well known: each advantage  generates 1 or n disadvantages.)
lies in the fact that the recursive traversal requires the processing of an SQL query on each function call.

Fortunately, there is an enhanced database structure that allows fast tree traversal:
A single SQL query does the job!


Run php (or other) scripts with suid root permission
Posted by pk on Sunday, September 07 2014 - 12:45:15
5 stars levelC Languagephp languageLinux operating system

Who never had the need to run some php (or other) scripts, which require access to data with root privilege, in the context of unprivileged users ( apache for an example ).

In fact, it is very easy to achieve this with a C program.

But in recent Linux distributions, for a script (other than bash/sh/...), it is now forbidden for so-called security considerations.

Maybe this would be justified on a server where multiple users have local access, with permissions that are uncontrolled by the administrator…

On a personal server, where only services (web, email, etc.) are offered to the public, I think that it is completely unfounded!

Let's see how to bypass totalitarian restrictions of current distributions.


 
yakpro rulez!

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