How FromQuery handles the memory usage?

[camohub]

I am not sure but as I know the library load the data from database in chunks. Can somebody tell me what happened when the chunk is consumed and send to the xsl. The chunk data are destroyed or leave in the memory? We have some huge tables with tens of thousands rows and I am not sure how the library handles Eloquent entities in the memory. Are they in the memory till the end of the script or are they deleted after the chunk is processed?
Thanks.