[TYPO3-mvc] Object = 3 queries; after toArray() = 1 query

[Stefan Frömken]

Hello MVC-Team,

I have activated MySQL-Debugging for table tt_news only. On my page I 
have a Fluid/Extbase-based Plugin which shows the last 3 tt_news-records.

When I assign these 3 records as an array of objects to fluid 
($query->execute()), then I can see that MySQL executes the SAME Query 3 
times one after the other.

When I assign these 3 records as an array of arrays to fluid 
($query->execute()->toArray()), then only ONE query will be executed.

Is there someone how can explain it to me?

Stefan