# Big Data in Smart City: Management Challenges
## 4 Transformation to Gaminess Big Data Framework
### GANMINESS Management System (GAMINESS Streaming Approach)
To host geospatial data features, the Oracle Spatial and Graph platform has a built-in geocoding and routing engine, allowing the quick implementation of customized solutions in the area of routing and navigation. It is worth noting that Oracle Spatial and the built-in routing engine were successfully utilized for routing within an IndoorGML (MLSEM) dataset in related research [66]. The IndoorGML source data could initially be transformed with FME. OpenTripPlanner (OTP) was the OSM routing engine selected for use with our proof of concept implementation. In their research, [PERSON] et al. [67] recommended 3 DCityDB as a platform for storage of transformed and adopted IndoorGML data, which provides good connectivity to other visualization (GIS and VR) platforms. For the implementation of the geosensors submodule, two standards (IoT and SWE) were considered. SWE is a set of standards which not only allows one to model sensor descriptions and observations but also specifies web services to exchange sensor descriptions and observations in an interoperable way. The combination of open standards (and APIs) eases the delivery of geospatial features and sensor observations in a coherent way and thereby supports interoperable and cross-domain city services [37]. The CityGML model is not able to represent time-dependent and dynamic properties. It allows storing properties as static values. The time-varying properties may be variations of spatial properties, or variation of thematic attributes, or variations with respect to sensor or real-time data. There is a technological gap when it comes to representing changing properties of the city or the city objects [38]. There are many existing open standards defined for unifying interfaces of the SW-IoT service layer. [PERSON] et al. proposed open and interoperable SW-IoT end-to-end architecture based on the OGC SensorThings API. The proposition was basfeed on three main components of the IoT-PNP: (1) a description file describing device metadata and capabilities, (2) a communication protocol between the gateway layer and the device layer for establishing connections, and (3) an automatic registration procedure for both sensing and tasking capabilities [38]. [PERSON] et al. concluded that the model of the city is generated independently using different sensor data, reconstruction methods, and software [68]. Resulting models often significantly differ in their geometry, appearance, and semantics. Those models are stored using different formats (XML, graphics, or binary formats), and their underlying data models often also differ. The problem with the CityGML encoded data is that software which supports CityGML is limited. There is a huge number of possible ways in which objects can be defined in CityGML, which makes the full implementation difficult. The 3 DCityDB as a database is built upon Oracle Spatial or PostGIS to store the CityGML data model in a relational database. Another model developed to store city models is CityJSON. This is a format which encodes a subset of the CityGML data model using JavaScript object notation (JSON). The problem with the CityJSON format is the limitation of some objects which are not covered with this model (Table 4). [PERSON] et al. (2020) said that most of the available 3D city models contain many geometric and topological errors. The most common errors are incomplete surfaces, duplicate vertices, self-intersecting volumes, etc. The GAMINESS management system offers the use of the automatic repair algorithm based on the CityGML topological rules. A relational database uses a structure that allows identification and access to data in relation to another piece of datum in the database. In a relational database, data are organized into tables. In the CityGML model, one or more classes of the UML diagram are often mapped in one table, where the table name corresponds to the class name. Classes are combined into a single table according to the class relations described in the UML class diagram of the model.