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A relational schema is a structure that represents the logical view or design of a database. It defines how the data is organized and the relationships between different entities or tables. It typically includes the names of the tables, their attributes or columns, and the constraints that define the relationships between them.
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The developer of a relational database refers to a file as?
In the context of a relational database, a file is typically referred to as a table. Tables are used to store structured data in rows and columns, allowing for efficient organization and retrieval of information. Each table represents a distinct entity or concept within the database schema.
What are the characteristics of relational table?
Relational tables are structured data representations, consisting of rows and columns where each row represents a unique record and each column represents a different attribute or field. They enforce a consistent schema, with data organized in a tabular format and support relationships between tables through keys. Relational databases ensure data integrity through constraints and support operations like querying and joining tables to retrieve or manipulate data efficiently.
Advantages and disadvantages of relational database?
Advantages: Data integrity: Ensures consistency and accuracy of data. Scalability: Able to handle large amounts of data and users. Flexibility: Supports complex queries and relational structures. Disadvantages: Performance: Slower compared to NoSQL databases for some use cases. Cost: Can be expensive to set up and maintain. Schema rigidity: Requires predefined schema, making it less suitable for unstructured data.
What is a relational completeness?
Relational completeness refers to the ability of a database management system to represent all relational operations and constraints. It ensures that the system can handle queries, updates, and integrity constraints effectively without compromising the accuracy or consistency of the data. Relational completeness is a key feature of relational database systems to ensure proper data management.
What is the importance of relational database?
Importance of relational database----------------------------------------------Relational databases can be considered as stores of information grouped together logically. Relational databases are used in all data related jobs. Especially in today's world of information, relational databases have increased importance, since they are used to store, manage, and retrieve data in a managed, organised and logical way. More information on relational databases, and their importance, can be found in detail here: http://tinyurl.com/relationaldatabase
How do you convert an ER diagram into a Relational Schema?
secret...know it yourself
What do you mean about schema in RDBMS?
In a relational database, the schema defines the tables, the fields in each table, and the relationships between fields and tables.
In a relational schema each tuple is divided into fields called?
In a relational schema, each tuple is divided into fields called attributes. Each attribute corresponds to a specific piece of data within the tuple.
What relation and relation schema?
Relational Schema refers to meta-data elements which are used to describe structures and constraints of data representing a particular http://wiki.answers.com/Describe_the_differences_in_meaning_between_the_terms_relation_and_relation_schema#. Whereas a relation is a property or predicate that ranges over more than one argumentHere's some translation from "Relational Algebra" to http://wiki.answers.com/Describe_the_differences_in_meaning_between_the_terms_relation_and_relation_schema#terminology:"Relation" = Table."Relation Schema" = Table definition.So for example, the "schema" for the Person "relation" is: Person(FirstName, LastName, Age, Gender, Address)Also in relational Algebra, a "tuple" is a table row, and an "attribute" is a table column.
What is a database schema?
A database schema is described in a formal language supported by the database management system (DBMS). In a relational database, the schema defines the tables, the fields in each table, and the relationships between fields and tables. Schemas are generally stored in a data dictionary. Although a schema is defined in text database language, the term is often used to refer to a graphical depiction of the database structure Levels of database schema 1. Conceptual schema, a map of concepts and their relationships 2. Logical schema, a map of entities and their attributes and relations 3. Physical schema, a particular implementation of a logical schema 4. Schema object, Oracle database object 5. Schema is the over all structure of the database
Describe the differences in meaning between the terms relation and relation schema?
Relational Schema refers to meta-data elements which are used to describe structures and constraints of data representing a particular domain. Whereas a relation is a property or predicate that ranges over more than one argument Here's some translation from "Relational Algebra" to SQL terminology: * "Relation" = Table. * "Relation Schema" = Table definition. So for example, the "schema" for the Person "relation" is: Person(FirstName, LastName, Age, Gender, Address) Also in relational Algebra, a "tuple" is a table row, and an "attribute" is a table column.Mathematician define a relation to be subset of cartesian product list of domains.In daabase relation is a set of entities with similar attributes.In other way we can consider a relation as a table and it's rows as entities, and table's columns as attributes.Concept of relation corresponds to programming language notion of variable.relational Schema corresponds to the programming language notion of type definition.It is the logical design of database.e.g. for a relation account having attributes account_number, branch_name and balance, relational schema is specified as -Account_schema= (account_number, branch_name, balance)
What is the semistructured model in adbms?
The semistructured model in advanced database management systems (ADBMS) allows for data to be stored without a strict schema like in relational databases. It provides flexibility in storing various types of data, allowing for different structures within the same database. This model is commonly used for data that does not conform to a fixed schema or where the schema may evolve over time.
The developer of a relational database refers to a file as?
In the context of a relational database, a file is typically referred to as a table. Tables are used to store structured data in rows and columns, allowing for efficient organization and retrieval of information. Each table represents a distinct entity or concept within the database schema.
Why 4NF is preferable then bcnf .with example?
Normalization is a process to reduce the redundancy by removing function dependencies BCNF (Boyece code normal form) has all functional dependencies A to B are trivial of discriminator should be superkey. To get relation in BCNF, Splitting the relation schema not neccessarily preserve all functional dependency, Loss less decomposition and dependency are main points for the normalization sometime, it is not possible to get a BCNF decomposition that is dependency, preserving. While 4NF has very similar definition as BCNF. A relational Schema is in 4NF, if all multivalued dependencies A to B are trivial and determinate A is superkey of schema. If a relational schema is in 4nf, it is already in BCNF. and 4NF decomposition preserve the all functional dependency. so 4NF is preferable than to have BCNF.
Functions of schema?
The schema (pronounced skee-ma) of a database system is its structure described in a formal language supported by the database management system (DBMS). In a relational database, the schema defines the tables, the fields, relationships, views, indexes, packages, procedures, functions, queues, triggers, types, sequences, materialized views, synonyms, database links, directories, Java, XML schema's and other elements.Schema's are generally stored in a data dictionary. Although a schema is defined in text database language, the term is often used to refer to a graphical depiction of the database structure.Hope this helps!Inclus - We provide indivdual and coporate trainingsEducate, Learn & Servewww.Inclus.net
What is star flake schema?
A starflake schema is a combination of a star schema and a snowflake schema. Starflake schemas are snowflake schemas where only some of the dimension tables have been denormalized. hardkingofflirt@gmail.com
What is schema and sub-schema?
The schema is the physical arrangement of the data as it appears in the DBMS. The subschema is the logical view of the data as it appears to the application program.
