Earticle

Internet accessibility has been growing due to the diffusion of smartphones in today's society. Therefore, people can generate data anywhere and are confronted with the challenge that they should process a large amount of data. Since the appearance of relational database management system (RDBMS), most of the recent information systems are built by utilizing it. RDBMS uses foreign-keys to avoid data duplication. The transactions in the database use attributes, such as atomicity, consistency, isolation, durability (ACID), which ensures that data integrity and processing results are stably managed. The characteristic of RDBMS is that there is high data reliability. However, this results in performance degradation. Meanwhile, from among these information systems, some systems only require high-performance rather than high reliability. In this case, if we only consider performance, the use of NoSQL provides many advantages. It is possible to reduce the maintenance cost of the information system that continues to increase in the use of open source software based NoSQL. And has a huge advantage that is easy to use NoSQL. Therefore, in this study, we prove that the leverage of NoSQL will ensure high performance than RDBMS by applying NoSQL to database systems that implement RDBMS.

Digital world is growing very fast and become more complex in the volume (terabyte to petabyte), variety (structured and un-structured and hybrid), velocity (high speed in growth) in nature. This refers to as ‘Big Data’ that is a global phenomenon. This is typically considered to be a data collection that has grown so large it can’t be effectively managed or exploited using conventional data management tools: e.g., classic relational database management systems (RDBMS) or conventional search engines. To handle this problem, traditional RDBMS are complemented by specifically designed a rich set of alternative DBMS; such as - NoSQL, NewSQL and Search-based systems. This paper motivation is to provide - classification, characteristics and evaluation of NoSQL databases in Big Data Analytics. This report is intended to help users, especially to the organizations to obtain an independent understanding of the strengths and weaknesses of various NoSQL database approaches to supporting applications that process huge volumes of data.

In order to utilize various data provided by Korea public open data portal, data should be systematically managed using a database. Since the range of open data is enormous, and the amount of data continues to increase, it is preferable to use a database capable of processing big data in order to analyze and utilize the data. This paper proposes data modeling and implementation method suitable for public data. The target data is subway related data provided by the public open data portal. Schema of the public data related to Seoul metro stations are analyzed and problems of the schema are presented. To solve these problems, this paper proposes a method to normalize and structure the subway data and model it in NoSQL database. In addition, the implementation result is shown by using MongDB which is a document-based database capable of processing big data.

이 논문에서는 NoSQL 데이터베이스의 동작 과정에서 발생하는 라이브러리 콜과 관련 정보들을 기록하여 내부 동작 과정을 심층적으로 분석하는 방법을 제안한다. 이를 통해 지정한 라이브러리 콜을 관찰 및 기록하며, 기록된 라이브러리 콜 정보를 통해 NoSQL 데이터베이스 간 내부 동작 차이를 비교하고, 입력 데이터 개수의 변화에 따라 발생하는 라이브러리 콜의 변화를 관찰하여 각 데이터베이스의 특징 및 확장성을 평가한다. 컴퓨팅 성능의 발전과 빅테이터의 활성화에 따라 다양하고 많은 양의 데이터를 기록 및 분석하기 위한 여러 종류의 NoSQL 데이터베이스가 등장하였으며, 각 환경에 적합한 데이터베이스를 선택하기 위해 각 데이터베이스의 확장성을 평가할 필요가 있다. 그러나 벤치마크, 성능 모델을 통한 외부 동작 관찰 또는 설계에 따른 구조적 특징 분석과 같은 기존의 방식으로는 데이터베이스가 동작하는 과정을 분석 또는 예측하기 어렵다. 따라서, 더욱 심층적인 분석을 통해 동작 과정 및 확장성을 파악하는 본 논문에서 제안하는 기법의 활용이 필요하다.

In this paper, we propose a method of in-depth analysis of internal operation process by recording library calls and related information that occur in the operation process of NoSQL database. It observes and records the specified library calls, compares the internal behavior differences between the NoSQL databases through recorded library call information, and evaluates the characteristics and scalability of each database by observing changes in the number of input data. The development of computing performance and the activation of big data have led to the emergence of different types of NoSQL databases for recording and analyzing various and large amounts of data, and it is necessary to evaluate the scalability of each database in order to select a database suitable for each environment. However, it is difficult to analyze or predict how a database operates in traditional ways, such as benchmarking, observing external behavior through performance models, or analyzing structural features based on design. Therefore, it is necessary to utilize the techniques proposed in this paper to understand the scalability of NoSQL databases with high accuracy.

We present our experiences with open-source NoSQL database systems in analyzing spatial and temporal astronomical data. We conduct experiments of using Redis in-memory NoSQL database system by modifying and exploiting its support of geohash for astronmical spatial data. Our experiment focuses on performance, cost, difficulty, and scalability of the database system. We also test OpenTSDB as a possible NoSQL database system to process astronomical time-series data. Our experiments include ingesting, indexing, and querying millions or billions of astronomical time-series measurements. We choose our KMTNet data and the public VVV (VISTA Variables in the Via Lactea) catalogs as test data. We discuss issues in using these NoSQL database systems in astronomy.

The New Vacuum Solar Telescope (NVST) is a 1-meter vacuum solar telescope that aims to observe the fine structures of active regions on the Sun. The main tasks of the NVST are high resolution imaging and spectral observations, including the measurements of the solar magnetic field. The NVST has been collecting more than 20 million FITS files since it began routine observations in 2012 and produces maximum observational records of 120 thousand files in a day. Given the large amount of files, the effective archiving and retrieval of files becomes a critical and urgent problem. In this study, we implement a new data archiving system for the NVST based on the Fastbit Not Only Structured Query Language (NoSQL) database. Comparing to the relational database (i.e., MySQL; My Structured Query Language), the Fastbit database manifests distinctive advantages on indexing and querying performance. In a large scale database of 40 million records, the multi-field combined query response time of Fastbit database is about 15 times faster and fully meets the requirements of the NVST. Our slestudy brings a new idea for massive astronomical data archiving and would contribute to the design of data management systems for other astronomical telescopes.