Find all prospect in the DB by showName and save to separate files

index.js

const MongoClient = require('mongodb').MongoClient
const assert = require('assert')
const Json2csvParser = require('json2csv').Parser
const Promise = require('bluebird')
const fs = Promise.promisifyAll(require('fs'))
const csvdata = require('csvdata')

let database
let collection
const fileWithShows = './data_5.csv'
const fileWithShowsTest = './data/test.csv'
const url = 'mongodb://localhost:27017'
const fields = ["id", "campaign_id", "salutation", "first_name", "last_name", "email", "company", "website", "job_title", "showname",  "department", "country", "address_one", "address_two", "city", "state", "territory", "zip", "phone", "fax", "source", "annual_revenue", "employees", "industry", "years_in_business", "comments", "notes", "score", "grade", "last_activity_at", "recent_interaction", "is_do_not_email", "is_do_not_call", "opted_out", "created_at", "updated_at", "TST_Dealer_Intro_Link", "TST_Custom_Banner_URL", "TST_Custom_Banner_Link", "TST_Custom_Goodbye", "TST_Custom_Headline", "TST_Custom_Thanks", "TST_Custom_Welcome", "TST_Custom_Welcome2", "TST_Dealer_Address1", "TST_Dealer_CityStateZip", "TST_Dealer_Contact", "TST_Dealer_Email", "TST_Dealer_Logo_Link", "TST_Dealer_Name", "TST_Dealer_Phone", "TST_Dealer_Website", "TST_Facebook_Link", "TST_Flickr_Link", "TST_LinkedIn_Link", "TST_Owner_Title", "TST_Pinterest_Link", "TST_Twitter_Link", "TST_YouTube_Link"]
const opts = { fields }

MongoClient.connect(url)
  .then(client => {
    database = client
    collection = client.db('myproject').collection('prospects')
    return client.db('myproject').collection('prospects')
  })
  .then(collection => {
    return csvdata.load(fileWithShows)
  })
  .then(shows => {
    return shows.map(({ showname }) => {
      return Promise.props({ data: collection.find({$or: [{ "showname.value": showname }, { showname: showname }]}), query: showname })
    })
  })
  .then(findPromises => {
    return Promise.all(findPromises)
  })
  .then(cursors => {
    return cursors.map(cursor => {
      return Promise.props({ data: cursor.data.toArray(), query: cursor.query })
    })
  })
  .then(toArrayPromises => {
    return Promise.all(toArrayPromises)
  })
  .then(collections => {
    return collections.map(collection => {
      return {
        data:collection.data.map(record => {
          if (record.showname && record.showname.value) {
            return Object.assign(record, {showname: record.showname.value.join(',')})
          }
          return record
        }),
        query: collection.query
      }
    })
  })
  .then(collections => {
    database.close()
    return collections.filter(collection => collection.data.length > 10).map(collection => {
      const parser = new Json2csvParser(opts)
      return { csv: parser.parse(collection.data), query: collection.query }
    })
  })
  .then(objects => {
    return objects.map((object, index) => {
      return fs.writeFileAsync( `res_from_db/${object.query}_${object.csv.split("\n").length - 1}.csv`, object.csv)
    })
  })
  .then(files => {
    return Promise.all(files)
  })
  .then(res => {
    console.log('Done')
  })
  .catch((err) => {
    console.log(err)
  })

Not optimized at all