Abstract: Provided are an apparatus and method for transmitting only sensor data actually used to process a user request among sensor data received from a sensor when communication restarts between a sensor data management device and a sensor data analysis device. Accordingly, the amount of data transmitted to the sensor data analysis device is reduced. The sensor data analysis device may analyze the sensor data received from the sensor data management device to process the user request.

Abstract: An apparatus and method for calculating the selectivity of a range query for multidimensional data using a multidimensional histogram are provided. A data space may be partitioned into one or more sub-spaces based on a sum of skew values of the one or more sub-spaces, a space-partitioning tree may be generated for the data space, and a multidimensional histogram may be generated for the data space based on the space-partitioning tree. A range query for multidimensional data may be processed based on the multidimensional histogram.

Abstract: An apparatus and method for calculating the selectivity of a range query for multidimensional data using a multidimensional histogram are provided. A data space may be partitioned into one or more sub-spaces based on a sum of skew values of the one or more sub-spaces, a space-partitioning tree may be generated for the data space, and a multidimensional histogram may be generated for the data space based on the space-partitioning tree. A range query for multidimensional data may be processed based on the multidimensional histogram.

Abstract: Provided are an apparatus and method for transmitting only sensor data actually used to process a user request among sensor data received from a sensor when communication restarts between a sensor data management device and a sensor data analysis device. Accordingly, the amount of data transmitted to the sensor data analysis device is reduced. The sensor data analysis device may analyze the sensor data received from the sensor data management device to process the user request.

Abstract: The present disclosure relates to a multi-dimensional histogram method using a minimal data-skew cover in a space-partitioning tree, which is used to estimate the selectivity of queries, that is, the sizes of query results, and a recording medium storing a program for executing the multi-dimensional histogram method. In the multi-dimensional histogram method, a Database (DB) system receives information required to generate a histogram from an outside of the DB system, and then constructs a space-partitioning tree based on the information required to generate a histogram. The DB system constructs a multi-dimensional histogram based on a minimal data-skew cover in the space-partitioning tree. When the DB system receives a query from the outside, the DB system calculates the estimate of the selectivity for the query by using the multi-dimensional histogram. Further, the present disclosure includes a recording medium storing a program for executing the multi-dimensional histogram method.