Aggregate (data warehouse)An aggregate is a type of summary used in dimensional models of data warehouses to shorten the time it takes to provide answers to typical queries on large sets of data. The reason why aggregates can make such a dramatic increase in the performance of a data warehouse is the reduction of the number of rows to be accessed when responding to a query. UseIn its simplest form, an aggregate is a simple summary table that can be derived by performing a Group by SQL query.
Dimension (data warehouse)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.
Fact tableIn data warehousing, a fact table consists of the measurements, metrics or facts of a business process. It is located at the center of a star schema or a snowflake schema surrounded by dimension tables. Where multiple fact tables are used, these are arranged as a fact constellation schema. A fact table typically has two types of columns: those that contain facts and those that are a foreign key to dimension tables.
Snowflake schemaIn computing, a snowflake schema or snowflake model is a logical arrangement of tables in a multidimensional database such that the entity relationship diagram resembles a snowflake shape. The snowflake schema is represented by centralized fact tables which are connected to multiple dimensions. "Snowflaking" is a method of normalizing the dimension tables in a star schema.
Star schemaIn computing, the star schema or star model is the simplest style of data mart schema and is the approach most widely used to develop data warehouses and dimensional data marts. The star schema consists of one or more fact tables referencing any number of dimension tables. The star schema is an important special case of the snowflake schema, and is more effective for handling simpler queries.
Time seriesIn mathematics, a time series is a sequence of data points indexed, listed, or graphed in chronological order. Most commonly, a time series consists of observations recorded at successive equally spaced points in time. Thus, it represents a form of discrete-time data. A time series may describe measurements collected over seconds, days, years, or even centuries.
Business processA business process, business method, or business function is a collection of related, structured activities or tasks performed by people or equipment in which a specific sequence produces a service or product (that serves a particular business goal) for a particular customer or customers. Business processes occur at all organizational levels and may or may not be visible to the customers.Foreign keyA foreign key is a set of attributes in a table that refers to the primary key of another table, linking these two tables.
Raw dataRaw data, also known as primary data, are data (e.g., numbers, instrument readings, figures, etc.) collected from a source. In the context of examinations, the raw data might be described as a raw score (after test scores).
Data warehouseIn computing, a data warehouse (DW or DWH), also known as an enterprise data warehouse (EDW), is a system used for reporting and data analysis and is a core component of business intelligence. Data warehouses are central 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.Fact constellationA fact constellation schema, also referred to as a galaxy schema, is a model using multiple fact tables and multiple dimension tables. These schemas are implemented for complex data warehouses. The fact constellation is a measure of online analytical processing and can be seen as an extension of the star schema. A fact constellation schema has multiple fact tables. It is a widely used schema and more complex than star schemas and snowflake schemas.
Dimension (data warehouse)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.Fact tableIn data warehousing, a fact table consists of the measurements, metrics or facts of a business process. It is located at the center of a star schema or a snowflake schema surrounded by dimension tables. Where multiple fact tables are used, these are arranged as a fact constellation schema. A fact table typically has two types of columns: those that contain facts and those that are a foreign key to dimension tables.Snowflake schemaIn computing, a snowflake schema or snowflake model is a logical arrangement of tables in a multidimensional database such that the entity relationship diagram resembles a snowflake shape. The snowflake schema is represented by centralized fact tables which are connected to multiple dimensions. "Snowflaking" is a method of normalizing the dimension tables in a star schema.Star schemaIn computing, the star schema or star model is the simplest style of data mart schema and is the approach most widely used to develop data warehouses and dimensional data marts. The star schema consists of one or more fact tables referencing any number of dimension tables. The star schema is an important special case of the snowflake schema, and is more effective for handling simpler queries.Time seriesIn mathematics, a time series is a sequence of data points indexed, listed, or graphed in chronological order. Most commonly, a time series consists of observations recorded at successive equally spaced points in time. Thus, it represents a form of discrete-time data. A time series may describe measurements collected over seconds, days, years, or even centuries.Business processA business process, business method, or business function is a collection of related, structured activities or tasks performed by people or equipment in which a specific sequence produces a service or product (that serves a particular business goal) for a particular customer or customers. Business processes occur at all organizational levels and may or may not be visible to the customers.Foreign keyA foreign key is a set of attributes in a table that refers to the primary key of another table, linking these two tables.Raw dataRaw data, also known as primary data, are data (e.g., numbers, instrument readings, figures, etc.) collected from a source. In the context of examinations, the raw data might be described as a raw score (after test scores).Data warehouseIn computing, a data warehouse (DW or DWH), also known as an enterprise data warehouse (EDW), is a system used for reporting and data analysis and is a core component of business intelligence. Data warehouses are central 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.Fact constellationA fact constellation schema, also referred to as a galaxy schema, is a model using multiple fact tables and multiple dimension tables. These schemas are implemented for complex data warehouses. The fact constellation is a measure of online analytical processing and can be seen as an extension of the star schema. A fact constellation schema has multiple fact tables. It is a widely used schema and more complex than star schemas and snowflake schemas.*As an Amazon Associate I earn from qualifying purchases.