Joining within a collection/Selecting a large set of values

Question

Hello everyone,
I'm testing DocumentDB for a new project, and at the moment I'm not sure if and how I can realize my use case. Lets say I have the following in my collection:
About 500000 employee records:
{  "Id": "1", "Type": "Employee", "Name": "testname", "Lastname": "testlastname" } // and much more
and I have team records
{  "Id": "45612354", "Type": "Team", "Teamname": "GreatTeam", "members": [ 1, 55049, 29969, 23492 ] }
There can be up to 50000 Teams with up to 10000 members each.
As Input, I've a specific team Id and I want to return all employee records of the team. In an RDBMS I would create two tables, query the team id and look for all member IDs in the employee table. How would I do this here?
I could let each member have a personal team list and look for the id, but then every query would need to look in the list of every employee -> potentially check millions of ids.
Is the join operator applicable in this case? Can I do it efficiently with an UDF like this one:
http://stackoverflow.com/questions/25637142/select-with-multiple-values-in-documentdb ? Is this a case where I should not use DocumentDB?
Thanks for your help.
Sebastian

Answer 1

not sure I want to be an employee that belongs to 1,000 teams, but ok :)
ok, so then you have a classic many:many relationship.
except in your case you really are talking about many.
have you read http://azure.microsoft.com/en-gb/documentation/articles/documentdb-modeling-data/ ?
in here I talk about how to model many:many relationships.
you basically have 2 options;
1. use mapping documents as you would have used a mapping table.
2. embed the relationship information on to the employee record and on to the team record.
because you can have up to 10,000 entries in an array you might start running in to some issues in terms of doc size if you embedded the data. depends on how many other properties an employee has.
try the following;
"employee": 1,
"teams": [
{"team": "A"},
{"team": "B"},
{"team": "C"},
{"team": "D"},
{"team": "E"}
"team" : "A",
"employees" : [
{"employee": 1},
{"employee": 2},
{"employee": 3},
{"employee": 4},
{"employee": 5}
that way you can search for employees given a team, and for teams given an employee.
however, like I said, I am not sure what this is going to do simply because you have very very very large arrays.
you will need to try it and see.