Why not ORM

Why not ORM? Michal Špaček, Skype; WebExpo 2010 , Prague

OMGWTF ORM ?

O bject- R elational M apping !

ORM, SRSLY ?

PHP/ORM guru , anyone ?
2010 © Skype – As seen on TV
Slide

ORM… … maps relational databases to objects says František Tröster

ORM… … maps relational databases to objects says František Tröster … maps objects to relational databases says Jiří Knesl

ORM… … maps relational databases to objects says František Tröster … maps objects to relational databases says Jiří Knesl … is a technique for converting data between incompatible type systems in OOP languages says Wiki Pedia

ORM is like …

… TDD

Best thing since sliced bread . Or maybe not .

ORM is said to allow the database systems swap „ on the fly “…

Slide

… , but have anyone seen it, ever ?

Most of the times you'll end up changing bunch of other things too, so it's not that easy as it might seem .

When your O/R mapper goes bananas …

ORM expert
Slide

Database system expert
Slide

Using ORM and want to refactor relations ?

Do it, pretty please, but you have to refactor code too…

… and you need to deploy all the changed stuff at once !

And what about accessing one database with several technologies?
Slide

Put your business logic into the database !

Issues solved ( all of them)
Slide

Database code can be tested separately from the rest of the code

Application code tests do not need a connection to the database

Forget explicit transactions ( BEGIN & COMMIT ) if you can has your codes wrapped in functions

You'll get …

Nice connection pooling
Slide

Every query can be executed on different machine

Add proxies…
Slide

… and get high performance clusters
Slide

Because we got no transactions

Teams of database developers and admins …

… can monitor functions and their performance

… can redirect functions to be executed in different database when something goes horribly wrong

… are generally useless while using ORM http://www.xkcd.com/303/ ORM, DUDE!

While without ORM …

… everything's possible!
Slide

Will YOU stop using ORM?

Problems summarized :
getting external help
refactoring relations
multiple technologies
tricky testing
inefficient connection pooling
admins are hopeless, if any
performance monitoring and control

Thanks for listening Michal Špaček Skype: spazef0rze ; Twitter: @ spazef0rze BTW, we're hiring: jobs.skype.com/cz

http://webexpo.cz	241
http://www.michalspacek.cz	31
http://webexpo.net	9
http://www.linkedin.com	7
http://www.webexpo.net	3
http://webexpo.innit.cz	1

Why not ORM

by Michal Špaček

Accessibility

Categories

Upload Details

Usage Rights

6 Embeds 292

Statistics

Why not ORM Presentation Transcript