Question: I recently learned about normalisation in my informatics class and I'm developing a multiplayer game using SQLite as backend database at the moment.

Some information on it:

The simplified structure looks a bit like the following:

```
 player_id |  level | exp  | money | inventory
---------------------------------------------------------
    1      |    3   | 120  | 400   | {item a; item b; item c}

```

Okay. As you can see, I'm storing a table/array in string form in the column "inventory". This is against normalization.

**But the thing is: Making an extra table for the inventory of players brings only disadvantages for me!**

* The only points where I access the database is:
	+ When a player joins the game and his profile is loaded
	+ When a player's profile is saved

When a player joins, I load his data from the DB and store it in memory. I only write to the DB like every five minutes when the player is saved. So there are actually very few SQL queries in my script.

If I used an extra table for the inventory I would have to, upon loading:

* Perform an performance and probably more data-intensive query to fetch all items from the inventory table which belong to player X
* Walk through the results and convert them into a table for storage in memory

And upon saving:

* Delete all items from the inventory table which belong to player X (player might have dropped/sold some items?)
* Walk through the table and perform a query for each item the player owns

If I kept all the player data in one table:

* I'd only have one query for saving and loading
* Everything would be in one place
* I would only have to (de)serialize the tables upon loading and saving, in my script

**What should I do now?**

**Do my arguments and situation justify working against normalisation?**

Answer: 
Are you saying that you think parsing a string out of "inventory" *doesn't* take any time or effort? Because everything you need to do to store/retrieve inventory items from a sub table is something you'd need to do with this string, and with the string you don't have any database tools to help you do it. 

Also, if you had a separate subtable for inventory items, you could add and remove items in real time, meaning that if the app crashes or the user disconnects, they don't lose anything.
Another case of premature optimization. 

You are trying to optimize something that you don't have any performance metrics. What is the target platform? Even crappiest computers nowadays could run at least hundreds of your reading operation per second. Then you add better hardware for more users, then you can go to cloud and when you come into problem space that Google, Twitter and Facebook are dealing with, you can consider denormalizing. Even then, best solution is some sort of key-value database.

Maybe you should check Wikipedia article on [Database Normalization](http://en.wikipedia.org/wiki/Database_normalization) to remind you why normalized database is a good thing.