how to use the puppetdb API to combine facts - api

Question

I'm using puppet version 5.3.6.
I'm able to query the puppetdb and get lots of useful information like this:
$ curl -s -X GET http://localhost:8080/pdb/query/v4/facts --data-urlencode 'query=["extract", [["function","count"],"value"],["=","name","operatingsystem"],["group_by", "value"]]' | python -mjson.tool
[
{
"count": 339,
"value": "OracleLinux"
},
{
"count": 73,
"value": "RedHat"
}
]
AND:
$ curl -s -X GET http://localhost:8080/pdb/query/v4/facts --data-urlencode 'query=["extract", [["function","count"],"value"],["=","name","operatingsystemmajrelease"],["group_by", "value"]]' | python -mjson.tool
[
{
"count": 38,
"value": "5"
},
{
"count": 217,
"value": "6"
},
{
"count": 157,
"value": "7"
}
]
How can I combine the two together and get each Oracle/Red Hat release & major release grouped together in an easy to see view. I've tried a few different ways to do it but I'm not able to find any examples or docs that can explain to me how to do it.
Other useful combinations would be all Red Hat servers in a particular DC running operatingsystemmajrelease 6 (or show all of them?). This would involve combining three facts.
This would be very ussful.
Thanks for your help!
Regards