PHP User Group Düsseldorf on 2014-09-23

Use the index, luke!

Last tuesday I finally made it to the PHP Usergroup in Düsseldorf. @andygrunwald invited me quite a few times to participate, so I was very happy to finally follow the invitation.

If you also want to participate or find out more about the group, you can check out the meetup.com page:

The event on Meetup: http://www.meetup.com/PHP-Usergroup-Duesseldorf/events/198343282/

The group on Meetup: http://www.meetup.com/PHP-Usergroup-Duesseldorf

I tried to summarize my impression of both talks and maybe you can take something away from that. So enjoy 😉

SQL – Stiefmütterliche SQL-Indizierung

by @markuswinandhttp://use-the-index-luke.com


  • Not many developers know how indexing really works.
  • Index and Query must match. As a developer we can either change the Index or the Query. We should do it.
  • We should know how to read execution plans (e.g. via EXPLAIN)
  • We should design our indexes and not just add them. Therefore we should know about every Query that exists so we can optimize for multiple Queries at once.

My takeaway

  • We should all read Markus’s stuff on his website, buy the book or hire him as a consultant. Although I have read some of his writings beforehand, he really knows how to present it to a crowd. And I like the austrian accent (my mother in law is austrian, too) 🙂

Reverse Engineering von Pfandbons

by @PlantProgrammer


  • The human brain is very good for recognizing patterns in small to medium
  • You can print money with Pfandbon Barcode manipulation

My takeaway

  • Very interesting to see the scientific method applied to real life situations, seems very useful
  • Software systems in all scenarios DO HAVE security problems
  • You can gain a lot of knowledge about black box systems by observing the input and output
  • Big companies are not very responsive to constructive criticism :/