Fix N+1 issue in TO-MANY recursive read operations

[Guillermo Gutiérrez]

Currently recursive read operations fetches relationships for the objects one by one, performing more SELECTs than strictly required. It could group elements and perform a single SELECT-WHERE-IN clause for each property, instead of a SELECT for each element of each property.

[Andy]

Is this being worked on currently or would you accept a pull request?

[Guillermo Gutiérrez]

I'm not working on it currently. Pull requests are always welcome ;)

[Guillermo Gutiérrez]

Fixed with Pull request #16