What are the Features of the Teradata Identity Columns? Wat Are The Most Important Options Of The Teradata Identity Column? GENERATED ALWAYS: Generate always a value, whether or not the query passes a value. GENERATED BY DEFAULT: Generate only a value if the column value delivered in the SQL insert statement is NULL. Used to copy

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Situation and Setup of a Historisation in Teradata Vantage Imagine that the time has come to improve your physical data model. Flawed or obsolete Teradata Vantage historisation design decisions need to be corrected. You are asked to merge tables of the same entity that hold different attributes in separation. We do not question why there

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What is the Waterfall Model? In the waterfall model, the data warehouse project is proceeding one phase after the other. Only when one phase is completed is the next phase started. The following phases will be passed through: Requirements Gathering (more about why I don’t like this term later) Design Implementation Verification (Testing, User Acceptance

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Introduction to Teradata Referential Integrity Teradata implements 3 Types of Referential Integrity 1. What is Standard Referential Integrity? With the Standard Referential Integrity, every INSERT, DELETE, or UPDATE of a Row is checked immediately whether the referential integrity is given. An additional reference index sub-table is required to ensure referential integrity. If referential integrity is

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To illustrate the impact these mistakes tend to have for Teradata Data Warehouse projects, let me compare it to a hospital team. Imagine the project is you who is about to receive costly and critical treatment. I am sure you do not want to hear staff exchanging conversation mentioned below before you doze off at

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What are Teradata Surrogate Keys? A surrogate key in Teradata is used to map the natural keys of source systems to a unique key, usually an integer value. Usually, one or more natural key columns are mapped to a surrogate key worthy of an INTEGER. Often a consecutive number is generated. For a surrogate key

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Without Teradata CHECK Constraint If a non-indexed column is used in a retrieving step (i.e., WHERE condition) and without Teradata Check Constraints, the Optimizer uses heuristics for missing statistics to estimate the number of rows in the answer set: The above estimation is 7,342 rows, which corresponds to 10% of the number of table rows.

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Improve the Performance of your Teradata System After executing the query below, you will probably be shocked by how only a few queries are consuming a significant part of the Teradata System resources. Performance tuning of these queries can make a huge difference in the overall system health. The overall system health itself highly depends on the

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What is Referential Integrity? Referential integrity defines relationships between tables based on a primary key and a foreign key.  It describes the columns in the referencing table, which are a foreign key in the referenced table. Referential integrity is a robust mechanism to ensure data consistency in a database. What is Soft Referential Integrity? Soft Referential

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OverviewWhat is A Data Model?What are the Major Types of Data Models?What is FS-LDM?How is FS-LDM Implemented?Dimensional ModelingDimensional Modeling (DM) is a modeling Technique in data warehousing, visually represented as a fact table surrounded by dimension tables.Some of the terms commonly used in this type of modeling:Dimension: A category of information. For example, the time

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