Optimizing ETL by a Two-Level Data Staging Method

2016 ◽  
Vol 12 (3) ◽  
pp. 32-50
Author(s):  
Xiufeng Liu ◽  
Nadeem Iftikhar ◽  
Huan Huo ◽  
Per Sieverts Nielsen

In data warehousing, the data from source systems are populated into a central data warehouse (DW) through extraction, transformation and loading (ETL). The standard ETL approach usually uses sequential jobs to process the data with dependencies, such as dimension and fact data. It is a non-trivial task to process the so-called early-/late-arriving data, which arrive out of order. This paper proposes a two-level data staging area method to optimize ETL. The proposed method is an all-in-one solution that supports processing different types of data from operational systems, including early-/late-arriving data, and fast-/slowly-changing data. The introduced additional staging area decouples loading process from data extraction and transformation, which improves ETL flexibility and minimizes intervention to the data warehouse. This paper evaluates the proposed method empirically, which shows that it is more efficient and less intrusive than the standard ETL method.

Author(s):  
Xiufeng Liu ◽  
Huan Huo ◽  
Nadeem Iftikhar ◽  
Per Sieverts Nielsen

Data warehousing populates data from different source systems into a central data warehouse (DW) through extraction, transformation, and loading (ETL). Massive transaction data are routinely recorded in a variety of applications such as retail commerce, bank systems, and website management. Transaction data record the timestamp and relevant reference data needed for a particular transaction record. It is a non-trivial task for a standard ETL to process transaction data with dependencies and high velocity. This chapter presents a two-tiered segmentation approach for transaction data warehousing. The approach uses a so-called two-staging ETL method to process detailed records from operational systems, followed by a dimensional data process to populate the data store with a star or snowflake schema. The proposed approach is an all-in-one solution capable of processing fast/slowly changing data and early/late-arriving data. This chapter evaluates the proposed method, and the results have validated the effectiveness of the proposed approach for processing transaction data.


Author(s):  
Huanyu Ouyang ◽  
John Wang

A data warehouse (DW) is a complete intelligent data storage and information delivery or distribution solution enabling users to customize the flow of information through their organization (Inmon & Hackathorn, 2002). It provides all authorized members of users’ organization with flexible, secure, and rapid access to critical information and intelligent reporting. DW can extract information from sources anywhere in the world and then delivers intelligence anywhere in the world. It connects to any platform, database, data source, and it will also scale to businesses and applications of any size. As early as the 1970’s, data warehousing software (DWS) was recognized when the earliest systems were first developed. The database designs of operational systems were not effective enough for the information analysis and reporting (The Data Warehousing Information Center, 2006).


Author(s):  
Ardhian Agung Yulianto

While data warehouse is designed to support the decision-making function, the most time-consuming part is Extract Transform Load (ETL) process. Case in Academic Data Warehouse, when data source came from faculty’s distributed database, although having a typical database but become not easier to integrate. This paper presents the ETL detail process following Data Flow Thread in data staging area for identifying, profiling, the content analyzing including all tables in data sources, and then cleaning, confirming dimension and data delivery to the data warehouse. Those processes are running gradually from each distributed database data sources until it merged. Dimension table and fact table are generated in a multidimensional model. ETL tool is Pentaho Data Integration 6.1. ETL testing is done by comparing data source and data target and DW testing conducted by comparing the data analysis between SQL query and Saiku Analytics plugin in Pentaho Business Analytic Server.


Author(s):  
Jose Maria Cavero ◽  
Carmen Costilla ◽  
Esperanza Marcos ◽  
Mario G. Piattini ◽  
Adolfo Sanchez

Data warehousing and online analytical processing (OLAP) technologies have become growing interest areas in recent years. Specific issues such as conceptual modeling, schemes translation from operational systems, physical design, etc. have been widely treated. A few methodologies covering the entire development cycle have also been proposed, but there is still not a general, accepted, complete methodology for data warehouse design. In this work we present a multidimensional data warehouse development methodology integrated within a traditional software development methodology.


Author(s):  
Evgenia R. Muntyan

The article analyzes a number of methods of knowledge formation using various graph models, including oriented, undirected graphs with the same type of edges and graphs with multiple and different types of edges. This article shows the possibilities of using graphs to represent a three-level structure of knowledge in the field of complex technical systems modeling. In such a model, at the first level, data is formed in the form of unrelated graph vertices, at the second level – information presented by a related undirected graph, and at the third level – knowledge in the form of a set of graph paths. The proposed interpretation of the structure of knowledge allows to create new opportunities for analytical study of knowledge and information, their properties and relationships.


Entropy ◽  
2021 ◽  
Vol 23 (5) ◽  
pp. 510
Author(s):  
Taiyong Li ◽  
Duzhong Zhang

Image security is a hot topic in the era of Internet and big data. Hyperchaotic image encryption, which can effectively prevent unauthorized users from accessing image content, has become more and more popular in the community of image security. In general, such approaches conduct encryption on pixel-level, bit-level, DNA-level data or their combinations, lacking diversity of processed data levels and limiting security. This paper proposes a novel hyperchaotic image encryption scheme via multiple bit permutation and diffusion, namely MBPD, to cope with this issue. Specifically, a four-dimensional hyperchaotic system with three positive Lyapunov exponents is firstly proposed. Second, a hyperchaotic sequence is generated from the proposed hyperchaotic system for consequent encryption operations. Third, multiple bit permutation and diffusion (permutation and/or diffusion can be conducted with 1–8 or more bits) determined by the hyperchaotic sequence is designed. Finally, the proposed MBPD is applied to image encryption. We conduct extensive experiments on a couple of public test images to validate the proposed MBPD. The results verify that the MBPD can effectively resist different types of attacks and has better performance than the compared popular encryption methods.


2003 ◽  
Vol 12 (03) ◽  
pp. 325-363 ◽  
Author(s):  
Joseph Fong ◽  
Qing Li ◽  
Shi-Ming Huang

Data warehouse contains vast amount of data to support complex queries of various Decision Support Systems (DSSs). It needs to store materialized views of data, which must be available consistently and instantaneously. Using a frame metadata model, this paper presents an architecture of a universal data warehousing with different data models. The frame metadata model represents the metadata of a data warehouse, which structures an application domain into classes, and integrates schemas of heterogeneous databases by capturing their semantics. A star schema is derived from user requirements based on the integrated schema, catalogued in the metadata, which stores the schema of relational database (RDB) and object-oriented database (OODB). Data materialization between RDB and OODB is achieved by unloading source database into sequential file and reloading into target database, through which an object relational view can be defined so as to allow the users to obtain the same warehouse view in different data models simultaneously. We describe our procedures of building the relational view of star schema by multidimensional SQL query, and the object oriented view of the data warehouse by Online Analytical Processing (OLAP) through method call, derived from the integrated schema. To validate our work, an application prototype system has been developed in a product sales data warehousing domain based on this approach.


2001 ◽  
Vol 10 (03) ◽  
pp. 377-397 ◽  
Author(s):  
LUCA CABIBBO ◽  
RICCARDO TORLONE

We report on the design of a novel architecture for data warehousing based on the introduction of an explicit "logical" layer to the traditional data warehousing framework. This layer serves to guarantee a complete independence of OLAP applications from the physical storage structure of the data warehouse and thus allows users and applications to manipulate multidimensional data ignoring implementation details. For example, it makes possible the modification of the data warehouse organization (e.g. MOLAP or ROLAP implementation, star scheme or snowflake scheme structure) without influencing the high level description of multidimensional data and programs that use the data. Also, it supports the integration of multidimensional data stored in heterogeneous OLAP servers. We propose [Formula: see text], a simple data model for multidimensional databases, as the reference for the logical layer. [Formula: see text] provides an abstract formalism to describe the basic concepts that can be found in any OLAP system (fact, dimension, level of aggregation, and measure). We show that [Formula: see text] databases can be implemented in both relational and multidimensional storage systems. We also show that [Formula: see text] can be profitably used in OLAP applications as front-end. We finally describe the design of a practical system that supports the above logical architecture; this system is used to show in practice how the architecture we propose can hide implementation details and provides a support for interoperability between different and possibly heterogeneous data warehouse applications.


Sign in / Sign up

Export Citation Format

Share Document