如何知道json对象的大小？

Question

这是我在mongodb上的记分板应用程序的架构。现在我无法理解一件事情，我怎样才能确保mongodb的大小不会高于16mb，条件是：

1. 你只能组建10支球队
2. 一支球队只能有12名球员。
3. 积分表将是非常小的团队
4. 匹配和历史数组将有大量数据

所以这就是问题

championships{
    "ChampionShip_Name":"IPL",
    "overs":"10",
    "config":[true,true,true],
    "NoofTeams":12,
    "teams":[{
            "teamname":"chennai superkings",
            "players":[{
                "playername":"sachin tendulkar",
                "skills":["batting","bowling"],
                "position":"opener"
            }]
            },{
            "teamname":"rajasthan royals",
            "players":[{
                "playername":"virendra sehwag",
                "skills":["batting","bowling"],
                "position":"opener"
            }]
            }],
    "pointstable":[

    ],
    "matchlist":[{
    "team1":"chennai superkings",
    "team2":"rajasthan royals",
    "winner":"rajasthan royals",
    "winningtag":"rajsthan royals won by 10"
    "inining1":["123","45.5","5"],
    "inining2":["124","12","4"]
    }]
}
Scoreboard{
team1:"indian",
team2:"pakistan",
inings:[{
batting:{
},
bowling:{
}
},{
batting:{
},
bowling:{
}
}
]
}