See the impact on document size of design decisions on the structure within a document

playground.js

// This is a playground for MongoDB for VS Code Extension.
// It creates 6 collections that each contain 1 document. All 6 collections 
// contain the same information but with different field names. This is to
// demonstrate the different ways that MongoDB can store the same data and what
// impact your design decisions have on document size (and therefore how many
// documents can fit in the database cache → performance).

use('FieldNames');
const schema1 = db.getCollection('schema1');
const schema2 = db.getCollection('schema2');
const schema3 = db.getCollection('schema3');
const schema4 = db.getCollection('schema4');
const schema5 = db.getCollection('schema5');
const schema6 = db.getCollection('schema6');

schema1.drop();
schema2.drop();
schema3.drop();
schema4.drop();
schema5.drop();
schema6.drop();

let doc = {};

for (let outer = 1; outer <= 10; outer++) {
  for(let middle = 1; middle <= 10; middle++) {
    for(let inner = 1; inner <= 10; inner++) {
      doc[`top_level_name_${outer}_middle_level_name_${middle}_bottom_level_name_${inner}`] = (inner % 2 !== 0) ? "Your data goes here" : "";
    }
  }
}

schema1.insertOne(doc);

doc = {};

for (let outer = 1; outer <= 10; outer++) {
  let middleLevel = {};
  for(let middle = 1; middle <= 10; middle++) {
    let innerLevel = {};
    for(let inner = 1; inner <= 10; inner++) {
      innerLevel[`bottom_level_name_${inner}`] = (inner % 2 !== 0) ? "Your data goes here" : "";
    }
    middleLevel[`middle_level_name_${middle}`] = innerLevel;
  }
  doc[`top_level_name_${outer}`] = middleLevel;
}

schema2.insertOne(doc);

doc = {};

for (let outer = 1; outer <= 10; outer++) {
  let middleLevel = {};
  for(let middle = 1; middle <= 10; middle++) {
    let innerLevel = {};
    for(let inner = 1; inner <= 10; inner++) {
      innerLevel[`bottom_level_name_${inner}`] = (inner % 2 !== 0) ? "Your data goes here" : null;
    }
    middleLevel[`middle_level_name_${middle}`] = innerLevel;
  }
  doc[`top_level_name_${outer}`] = middleLevel;
}

schema3.insertOne(doc);

doc = {};

for (let outer = 1; outer <= 10; outer++) {
  let middleLevel = {};
  for(let middle = 1; middle <= 10; middle++) {
    let innerLevel = {};
    for(let inner = 1; inner <= 10; inner++) {
      if (inner % 2 !== 0) {
        innerLevel[`bottom_level_name_${inner}`] = "Your data goes here";
      }
    }
    middleLevel[`middle_level_name_${middle}`] = innerLevel;
  }
  doc[`top_level_name_${outer}`] = middleLevel;
}

schema4.insertOne(doc);

doc = {};

for (let outer = 1; outer <= 10; outer++) {
  let middleLevel = {};
  for(let middle = 1; middle <= 10; middle++) {
    let innerLevel = {};
    for(let inner = 1; inner <= 10; inner++) {
      if (inner % 2 !== 0) {
        innerLevel[`bottomLevelName${inner}`] = "Your data goes here";
      }
    }
    middleLevel[`middleLevelName${middle}`] = innerLevel;
  }
  doc[`topLevelName${outer}`] = middleLevel;
}

schema5.insertOne(doc);

doc = {};

for (let outer = 1; outer <= 10; outer++) {
  let middleLevel = {};
  for(let middle = 1; middle <= 10; middle++) {
    let innerLevel = {};
    for(let inner = 1; inner <= 10; inner++) {
      if (inner % 2 !== 0) {
        innerLevel[`c${inner}`] = "Your data goes here";
      }
    }
    middleLevel[`b${middle}`] = innerLevel;
  }
  doc[`a${outer}`] = middleLevel;
}

schema6.insertOne(doc);