Object-relational database

Descrição

All of the above was reproduced courtesy of Mohsan Ali.
adamelvin786
Mapa Mental por adamelvin786, atualizado more than 1 year ago
adamelvin786
Criado por adamelvin786 mais de 11 anos atrás
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Resumo de Recurso

Object-relational database
  1. Features
    1. Advantages
      1. Ease of use
        1. Flexibility
          1. Precision
            1. Security
              1. Data Independence
                1. Data Manipulation Language
                2. Disadvantages
                  1. machine performance
                    1. Schema Changes
                      1. Language Dependence
                        1. Lack of Ad-Hoc Queries
                      2. object types
                        1. model real-world entities
                          1. Object Columns
                            1. An object column is a column in a table that is defined using an object type.
                            2. Object Tables
                              1. object table is a table in which each row contains one object of a given object type.
                            3. NULL
                              1. atomic NULL
                                1. object can be atomically NULL
                                  1. cannot be updated
                                2. NULL attributes
                                  1. object can have attributes that are NULL
                                    1. Updates on its individual attributes
                                      1. Must use cascade clause
                                3. collection types
                                  1. VARRAY
                                    1. variable sized array which has ordered set of data elements of the same type.
                                    2. Nested tables
                                      1. Tables are ordered set of elements of the same data type