Flashcards
Data Warehouse and OLAP
Cards in this deck (12)
- 1Data WarehouseA subject-orientated, integrated, time-variant and non-volatile collection of data in the support of making decisions.
- 2Subject-orientatedThe organisation of data into topics. The focus is put on data modelling and analysis, not daily operations or transactions.
- 3IntegrationContains multiple data sources. At this stage data is converted and cleaned to ensure consistency.
- 4Time-variantThe warehouse stores all historical data. Every key structure has a valid-time and transaction time attached to it.
- 5Non-volatileData warehouses contain the copy of the transaction from its operational environment. Data cannot be updated or changed.
- 6OLAP (Online Analytical Processing)Software tool for data analysis and decision making.
Allows interactive exploitation analysis to discover patterns. - 7OLTP (Online Transaction Process)Provides real-time processing of SQL transactions for day to day use. Supports E-commerce and other applications. E.g purchasing inventory, banking, payroll, manufacturing etc.
- 8Data Warehouse Designs- Star Schema
- Snowflakes schema
-Starflakes schema - 9Star SchemaLogical structure that has factual data in the centre surrounded with reference data around it.
- 10Snowflakes SchemaStar schema doesn't contain denormalised data.
- 11Starflakes schemaHybrid structure that contains both star and snowflakes.
- 12Why separate the data warehouses?- High performance for both systems.
- Warehouse is tuned for OLAP. The warehouse enables multi-dimensional views.
-Different functions, data from different sources makes could be inconsistent such as the name and type.
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- Bachelors Degree Data Mining Flashcards on Data Warehouse and OLAP, created by Jason Dsilva on 28/04/2016.
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- Jason Dsilva
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