code: function vacuum(connection, done) {
    var n = connection.connectionManager.dialectName;
    var query;
  
    // Make query based on dialiect
    if (n === "mysql" || n === "mariadb" || n === "mysqli") {
      query = "SELECT 1";
    }
    else if (n === "sqlite") {
      query = "VACUUM";
    }
    else if (n === "pgsql" || n === "postgres") {
      query = "VACUUM";
    }
  
    runQuery(connection, query, { type: connection.QueryTypes.UPSERT, raw: true }, done);
  }
docs: Run vaccume query