Object.nearby Function Slow and Blocking about loopback-connector-mysql HOT 8 CLOSED

max = Number(max || 10);

var geo = here.split(/,\s*/);
var lat = geo[1];
var lng = geo[0];

var table = 'person';
var column = 'location';

var sql = 'SELECT x.id from ( \
            SELECT id, ( \
                  6373 * acos ( \
                  cos ( radians( ' + lat + ' ) ) \
                  * cos( radians( X(' + column + ') ) ) \
                  * cos( radians( Y(' + column + ') ) - radians( ' + lng + ' ) ) \
                  + sin ( radians( ' + lat + ' ) ) \
                  * sin( radians( X(' + column + ') ) ) \
                ) \
            ) AS distance \
          FROM ' + table + ' \
              ORDER BY distance \
              ) x \
          WHERE x.distance < ' + max + ';';

Person.app.datasources.mysql.connector.query(sql, function(err, result) {
  if (err) {
    console.log('Error retrieving persons nearby ...');
    console.log(err);
    return next(err);
  }

  var ids = [];
  for (var i = 0; i < result.length; i++) {
    ids.push(result[i].id);
  };

  Person.find({
    'where': {
      'id': {
        'inq': ids
      }
    }
  }, function(err, res) {
    next(err, res);
  });
});

  "location": {
    "type": "geopoint",
    "required": true
  },

  Event.nearby = function([lat, lng], distance = 5, {limit = 10, skip = 0} = {}, cb) {
    const userLocation = new GeoPoint({
      lat,
      lng,
    });

    const sql = `SELECT * from
      (SELECT *, (ST_Distance_Sphere(ST_GeomFromText('POINT(${lng} ${lat})'), location, 6373))
      AS distance FROM mydb.Event) x WHERE x.distance <= ${distance} ORDER BY distance LIMIT ${limit} OFFSET ${skip};`;

    const ds = Event.app.dataSources.db;
    const mySQLPool = ds.connector.client;
    mySQLPool.query(sql,
    function(err, rows, fields) {
      if (err) return cb(err);

      return cb(null, rows);
    });
  };