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Conformed Dimension
A dimension is a structure that categorizes facts and measures in order to enable users to answer business questions. Commonly used dimensions are people, products, place and time. (Note: People and time sometimes are not modeled as dimensions.) In a data warehouse, dimensions provide structured labeling information to otherwise unordered numeric measures. The dimension is a data set composed of individual, non-overlapping data elements. The primary functions of dimensions are threefold: to provide filtering, grouping and labelling. These functions are often described as " slice and dice". A common data warehouse example involves sales as the measure, with customer and product as dimensions. In each sale a customer buys a product. The data can be sliced by removing all customers except for a group under study, and then diced by grouping by product. A dimensional data element is similar to a categorical variable in statistics. Typically dimensions in a data warehouse are organi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Warehouse
In computing, a data warehouse (DW or DWH), also known as an enterprise data warehouse (EDW), is a system used for Business intelligence, reporting and data analysis and is a core component of business intelligence. Data warehouses are central Repository (version control), repositories of data integrated from disparate sources. They store current and historical data organized in a way that is optimized for data analysis, generation of reports, and developing insights across the integrated data. They are intended to be used by analysts and managers to help make organizational decisions. The data stored in the warehouse is uploaded from operational systems (such as marketing or sales). The data may pass through an operational data store and may require data cleansing for additional operations to ensure data quality before it is used in the data warehouse for reporting. The two main workflows for building a data warehouse system are extract, transform, load (ETL) and extract, load, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Business Fact
Business is the practice of making one's living or making money by producing or buying and selling products (such as goods and services). It is also "any activity or enterprise entered into for profit." A business entity is not necessarily separate from the owner and the creditors can hold the owner liable for debts the business has acquired except for limited liability company. The taxation system for businesses is different from that of the corporates. A business structure does not allow for corporate tax rates. The proprietor is personally taxed on all income from the business. A distinction is made in law and public offices between the term business and a company (such as a corporation or cooperative). Colloquially, the terms are used interchangeably. Corporations are distinct from sole proprietors and partnerships. Corporations are separate and unique legal entities from their shareholders; as such they provide limited liability for their owners and members. Corporat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Categorical Variable
In statistics, a categorical variable (also called qualitative variable) is a variable that can take on one of a limited, and usually fixed, number of possible values, assigning each individual or other unit of observation to a particular group or nominal category on the basis of some qualitative property. In computer science and some branches of mathematics, categorical variables are referred to as enumerations or enumerated types. Commonly (though not in this article), each of the possible values of a categorical variable is referred to as a level. The probability distribution associated with a random categorical variable is called a categorical distribution. Categorical data is the statistical data type consisting of categorical variables or of data that has been converted into that form, for example as grouped data. More specifically, categorical data may derive from observations made of qualitative data that are summarised as counts or cross tabulations, or from observat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central European Time
Central European Time (CET) is a standard time of Central, and parts of Western Europe, which is one hour ahead of Coordinated Universal Time (UTC). The UTC offset, time offset from UTC can be written as UTC+01:00. It is used in most parts of Europe and in several African countries. CET is also known as Middle European Time (MET, German: :de:Mitteleuropäische Zeit, MEZ) and by colloquial names such as Amsterdam Time, Berlin Time, Brussels Time, Budapest Time, Madrid Time, Paris Time, Stockholm Time, Rome Time, Prague time, Warsaw Time or Romance Standard Time (RST). The 15th meridian east is the central axis per UTC+01:00 in the world system of time zones. As of 2023, all member state of the European Union, member states of the European Union observe summer time (daylight saving time), from the last Sunday in March to the last Sunday in October. States within the CET area switch to Central European Summer Time (CEST, UTC+02:00) for the summer. The next change to CET is scheduled ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coordinated Universal Time
Coordinated Universal Time (UTC) is the primary time standard globally used to regulate clocks and time. It establishes a reference for the current time, forming the basis for civil time and time zones. UTC facilitates international communication, navigation, scientific research, and commerce. UTC has been widely embraced by most countries and is the effective successor to Greenwich Mean Time (GMT) in everyday usage and common applications. In specialised domains such as scientific research, navigation, and timekeeping, other standards such as Universal Time, UT1 and International Atomic Time (TAI) are also used alongside UTC. UTC is based on TAI (International Atomic Time, abbreviated from its French name, ''temps atomique international''), which is a weighted average of hundreds of atomic clocks worldwide. UTC is within about one second of mean solar time at 0° longitude, the currently used prime meridian, and is not adjusted for daylight saving time. The coordination of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Date-timestamp
A timestamp is a sequence of characters or encoded information identifying when a certain event occurred, usually giving date and time of day, sometimes accurate to a small fraction of a second. Timestamps do not have to be based on some absolute notion of time, however. They can have any epoch, can be relative to any arbitrary time, such as the power-on time of a system, or to some arbitrary time in the past. A distinction is sometimes made between the terms datestamp, timestamp and date-timestamp: * Datestamp or DS: A date, for example -- according to ISO 8601 * Timestamp or TS: A time of day, for example :: using 24-hour clock * Date-timestamp or DTS: Date and time, for example --, :: History The term "timestamp" derives from rubber stamps used in offices to stamp the current date, and sometimes time, in ink on paper documents, to record when the document was received. Common examples of this type of timestamp are a postmark on a letter or the "in" and "out" times on a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuple-versioning
Tuple-versioning (also called point-in-time) is a mechanism used in a relational database management system to store past states of a relation. Normally, only the current state is captured. Using tuple-versioning techniques, typically two values for time are stored along with each tuple: a start time and an end time. These two values indicate the validity of the rest of the values in the tuple. Typically when tuple-versioning techniques are used, the current tuple has a valid start time, but a null value for end time. Therefore, it is easy and efficient to obtain the current values for all tuples by querying for the null end time. A single query that searches for tuples with start time less than, and end time greater than, a given time (where null end time is treated as a value greater than the given time) will give as a result the valid tuples at the given time. For example, if a person's job changes from Engineer to Manager, there would be two tuples in an Employee table ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ralph Kimball
Ralph Kimball (born July 18, 1944) is an author on the subject of data warehousing and business intelligence. He is one of the original architects of data warehousing and is known for long-term convictions that data warehouses must be designed to be understandable and fast. His bottom-up methodology, also known as dimensional modeling or the Kimball methodology, is one of the two main data warehousing methodologies alongside Bill Inmon. He is the principal author of the best-selling books ''The Data Warehouse Toolkit'' (1996), ''The Data Warehouse Lifecycle Toolkit'' (1998), ''The Data Warehouse ETL Toolkit'' (2004) and ''The Kimball Group Reader'' (2015), published by Wiley and Sons. Career After receiving a Ph.D. in 1973 from Stanford University in electrical engineering (specializing in man-machine systems), Ralph joined the Xerox Palo Alto Research Center (PARC). At PARC Ralph was a principal designer of the Xerox Star Workstation, the first commercial product to use mice ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extract, Transform, Load
Extract, transform, load (ETL) is a three-phase computing process where data is ''extracted'' from an input source, ''transformed'' (including cleaning), and ''loaded'' into an output data container. The data can be collected from one or more sources and it can also be output to one or more destinations. ETL processing is typically executed using software applications but it can also be done manually by system operators. ETL software typically automates the entire process and can be run manually or on recurring schedules either as single jobs or aggregated into a batch of jobs. A properly designed ETL system extracts data from source systems and enforces data type and data validity standards and ensures it conforms structurally to the requirements of the output. Some ETL systems can also deliver data in a presentation-ready format so that application developers can build applications and end users can make decisions. The ETL process is often used in data warehousing. ETL sys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Integration
Data integration refers to the process of combining, sharing, or synchronizing data from multiple sources to provide users with a unified view. There are a wide range of possible applications for data integration, from commercial (such as when a business merges multiple databases) to scientific (combining research data from different bioinformatics repositories). The decision to integrate data tends to arise when the volume, complexity (that is, big data) and need to share existing data explodes. It has become the focus of extensive theoretical work, and numerous open problems remain unsolved. Data integration encourages collaboration between internal as well as external users. The data being integrated must be received from a heterogeneous database system and transformed to a single coherent data store that provides synchronous data across a network of files for clients. A common use of data integration is in data mining when analyzing and extracting information from exist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surrogate Key
A surrogate key (or synthetic key, pseudokey, entity identifier, factless key, or technical key) in a database is a unique identifier for either an ''entity'' in the modeled world or an ''object'' in the database. The surrogate key is ''not'' derived from application data, unlike a ''natural'' (or ''business'') key. Definition There are at least two definitions of a surrogate: ; Surrogate (1) – Hall, Owlett and Todd (1976): A surrogate represents an ''entity'' in the outside world. The surrogate is internally generated by the system but is nevertheless visible to the user or application. ; Surrogate (2) – Wieringa and De Jonge (1991): A surrogate represents an ''object'' in the database itself. The surrogate is internally generated by the system and is invisible to the user or application. The ''Surrogate (1)'' definition relates to a data model rather than a storage model and is used throughout this article. See Date (1998). An important distinction between a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Performance Improvement
Performance improvement is measuring the output of a particular business process or procedure, then modifying the process or procedure to increase the Output (economics), output, increase efficiency (economics), efficiency, or increase the effectiveness of the process or procedure. Performance improvement can be applied to either individual performance, such as an athlete, or organisational performance, such as a racing team or a commercial business. The United States Coast Guard has published the ''Performance Improvement Guide (PIG)'', which describes various processes and tools for performance management at the individual and organisational levels. Organisational development In organisational development, performance improvement is an organisational change in which the Management, managers and Board of directors, governing body of an organisation put into place and manage a program which measures the current level of performance of the organisation. It then generates ideas f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
