relational data model concepts
The Relational Data Model and Relational Database Constraints
... key. Relational Model Concepts The relational Model of Data is based on the concept of a Relation.A Relation is a mathematical concept based on the ideas of sets.The strength of the relational ... has three tuples. Relational Model Concepts The model was first proposed by Dr. E.F. Codd of IBM in 1970 in the following paper:"A Relational Model for Large Shared Data Banks," ... DomainTable Definition Schema of a RelationPopulated Table Extension The Relational Data Model and Relational Database Constraints
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Chương 3: Mô hình quan hệ (Relational Data Model) potx
... thuộc tính của một quan hệ luôn là siêukhóa. 11CƠ SỞ DỮ LIỆUChương 3MÔ HÌNH QUAN HỆ (Relational Data Model) 2Chương 3 MÔ HÌNH QUAN HỆI. Một số khái niệmĐịnh nghóa quan hệKhóa của quan hệII....
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Oracle Data Guard Concepts and Administration
... Standby Databases 7-117.2.1 Switchovers Involving a Physical Standby Database 7-117.2.2 Failovers Involving a Physical Standby Database 7-14 Data Guard Services1-4 Oracle Data Guard Concepts ... the redo data to be archived first at the standby database.■Role Management ServicesChange the role of a database from a standby database to a primary database, or from a primary database ... standby database is created and configured, Data Guard automatically maintains the standby database by transmitting primary database redo data to the standby system, where the redo data is...
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Oracle9i Data Mining Concepts Release 9.2.0.2 October 2002 Part No. A95961-02 Oracle9i Data
... Basic ODM Concepts 1-11Basic ODM Concepts Oracle9i Data Mining (ODM) embeds data mining within the Oracle9i database. The data never leaves the database — the data, data preparation, model building, ... preprocessing as the data used to build the model. ODM AlgorithmsBasic ODM Concepts 1-15After building the specified models, Model Seeker evaluates each model by testing and calculating lift. Model Seeker ... 1.2 Oracle9i Data Mining ComponentsOracle9i Data Mining has two main components:■Oracle9i Data Mining API ■ Data Mining Server (DMS)1.2.1 Oracle9i Data Mining APIThe Oracle9i Data Mining...
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Tài liệu Activity 4.2: Creating a Logical Data Model ppt
... Activity 4.2: Creating a Logical Data Model In this activity, you will use the skills learned in this module to define the relationships within a logical data model and produce a sample ER diagram ... Activity 4.2: Creating a Logical Data Model 19 Exercise 2: Determining Cardinality and Existence In this exercise, you will ... activity, you will be able to: ! Identify relationships between entities. ! Create a logical data model. Before You Begin This activity will take place in small groups with a class discussion...
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Tài liệu NoSQL Database Technology: Post-relational data management for interactive software systems docx
... their own database technologies. These “NoSQL” databases, each eschewing the relational data model, are a far better match for the needs modern interactive software systems. NOSQL DATABASE ... DenormalizingBefore storing data in an RDBMS, a schema must be created dening precisely what data can be stored in the database and the relationships between data elements. Data is decomposed into ... easier and allows for rapid changes in the data model. Of course, just about all relational database functionality is lost in the process (though if the database is sharded, much of the functionality...
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Báo cáo khoa học: "A Flexible Stand-Off Data Model with Query Language for Multi-Level Annotation" ppt
... associative relations representing e.g.coreference.2 The Data Model We propose a stand-off data model implemented inXML. The basedata is stored in a simple XML file1The current release version ... token queries exactly one basedata element(i.e. word) or one markable.3.1 Query TokensBasedata elements can be queried by matching reg-ular expressions. Each basedata query token con-sists ... of the relationsof their basedata elements.While it has become common practice to usethe stand-off mechanism to relate several annota-tion levels to one basedata file, it is also not un-common...
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Báo cáo khoa học: "Towards A Modular Data Model For Multi-Layer Annotated Corpora" docx
... exists.2 Data modelsThere are three purposes data models can serve.The first purpose is context suitability. A data model used for this purpose must reflect as wellas possible the data the user ... lowlevel data storage model rather than a high levelannotation data model. A high level query language is necessary to get agood user acceptance and to achieve independencefrom lower level data models ... anno-tated multi-modal data. NXT is based on the NITEObject Model (NOM) which is an extension of theXML data model. NOM features a similar separa-tion of tiers as the PACE-Ling data model, but ismore...
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The POSTGRES Data Model
... extended with user-defined procedures. Section 5compares the model with other data models and section 6 summarizes the paper.2. Data Model A database is composed of a collection of relations that ... object-oriented model, but it does so without discarding the relational model and without having to introduce a new confusing terminology.6. SummaryThe POSTGRES data model uses the ideas of abstract data ... of abstract data types, data of type procedure,and inheritance to extend the relational model. These ideas can be used to simulate a variety ofsemantic data modeling concepts (e.g., aggregation...
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Data Mining Concepts and Techniques phần 1 potx
... Advanced database systems include object -relational databases andspecific application-oriented databases, such as spatial databases, time-series databases,text databases, and multimedia databases. ... data repository, as well as to transient data, such as data streams. Thus the scope of ourexamination of data repositories will include relational databases, data warehouses,transactional databases, ... constructed for relational databases.An ER data model represents the database as a set of entities and their relationships.Consider the following example.Example 1.1A relational database for...
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Data Mining Concepts and Techniques phần 2 ppsx
... section describes both data integration and data transformation.2.4.1 Data IntegrationIt is likely that your data analysis task will involve data integration, which combines data from multiple ... 972.7Summary Data preprocessing is an important issue for both data warehousing and data mining,as real-world data tend to be incomplete, noisy, and inconsistent. Data preprocessingincludes data cleaning, ... cleaning, data integration, data transformation, and data reduction.Descriptive data summarization provides the analytical foundation for data pre-processing. The basic statistical measures for data...
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Data Mining Concepts and Techniques phần 3 docx
... warehousingtechnology.3.3.4 Metadata RepositoryMetadata are data about data. When used in a data warehouse, metadata are the data thatdefine warehouse objects. Figure 3.12 showed a metadata repository within ... the field of data mining, substantial research has been performed for data mining onvarious platforms, including transaction databases, relational databases,spatial databases,text databases, ... Most data mining tools need to workon integrated, consistent, and cleaned data, which requires costly data clean-ing, data integration, and data transformation as preprocessing steps. A data warehouse...
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