DATABASE MANAGEMENT SYSTEMS 1. Define Database
... A super key is a set of one or more attributes that collectively allows us to identify uniquely an entity in the entity set. 37. Define- relational algebra. The relational algebra is a procedural query language. It consists of a set of operations that take one or two relation as input and produce a ...
... A super key is a set of one or more attributes that collectively allows us to identify uniquely an entity in the entity set. 37. Define- relational algebra. The relational algebra is a procedural query language. It consists of a set of operations that take one or two relation as input and produce a ...
Data Models - Lsp4you.com
... •The record type at the top of the tree is usually known as root. •In general, the root may have any number of dependents and each of these dependents may have any number of low level dependents and so on. Consider the hierarchical view of the above sample database of suppliers, items and ...
... •The record type at the top of the tree is usually known as root. •In general, the root may have any number of dependents and each of these dependents may have any number of low level dependents and so on. Consider the hierarchical view of the above sample database of suppliers, items and ...
An Implementation for Nested Relational Databases
... use indexing techniques to improve access time. Typically, indexes are built on all or some of the attributes of a relation. A value of the index maps to a list of tuple-identifiers of tuples that contain the value of the indexed attribute. Our approach to indexing follows the domain based approach ...
... use indexing techniques to improve access time. Typically, indexes are built on all or some of the attributes of a relation. A value of the index maps to a list of tuple-identifiers of tuples that contain the value of the indexed attribute. Our approach to indexing follows the domain based approach ...
Chapter 17: Parallel Databases
... Pi,j computes the join of ri with sj. In order to do so, ri is replicated to Pi,0, Pi,1, ..., Pi,m-1, while si is replicated to P0,i, P1,i, ..., Pn-1,i ...
... Pi,j computes the join of ri with sj. In order to do so, ri is replicated to Pi,0, Pi,1, ..., Pi,m-1, while si is replicated to P0,i, P1,i, ..., Pn-1,i ...
Relation.
... Example: given entity set instructor with composite attribute name with component attributes first_name and last_name the schema corresponding to the entity set has two attributes name_first_name and ...
... Example: given entity set instructor with composite attribute name with component attributes first_name and last_name the schema corresponding to the entity set has two attributes name_first_name and ...
Lecture Notes
... • Next step is to identify attributes of those entities. • An attribute is labeled piece of information (i.e., a name/value pair) • In general, we expect every instance of a particular entity to have specific values for a set of common attributes. ...
... • Next step is to identify attributes of those entities. • An attribute is labeled piece of information (i.e., a name/value pair) • In general, we expect every instance of a particular entity to have specific values for a set of common attributes. ...
Relational Databases
... – Specify the following constraints (in BON and in SQL): • a sailor’s rating must be an integer in the range 1 to 10 • no sailor can reserve a green boat ...
... – Specify the following constraints (in BON and in SQL): • a sailor’s rating must be an integer in the range 1 to 10 • no sailor can reserve a green boat ...
CS211 Lecture: Persistence; Introduction to Relational Databases
... Note that there are multiple rows for studentID 3333333 and for facultyID 1, but there can be only one row for studentID 3333333 and facultyID 1. 2. The primary key of a relation (table) representing a relationship is thus typically composite - and may be the whole scheme (if the relationship has no ...
... Note that there are multiple rows for studentID 3333333 and for facultyID 1, but there can be only one row for studentID 3333333 and facultyID 1. 2. The primary key of a relation (table) representing a relationship is thus typically composite - and may be the whole scheme (if the relationship has no ...
Relational Algebra
... Structures, Constraints, Operations – Relational Algebra – Relational Calculus – The languages SQL and QBE ...
... Structures, Constraints, Operations – Relational Algebra – Relational Calculus – The languages SQL and QBE ...
Session-7: Object-Relational DBMS
... programming languages (handling one row of data at a time) and SQL (multiple row handling) which makes conversions inefficient. Relational people say, instead of defining new models, let’s introduce set-level functionality into programming languages. ...
... programming languages (handling one row of data at a time) and SQL (multiple row handling) which makes conversions inefficient. Relational people say, instead of defining new models, let’s introduce set-level functionality into programming languages. ...
syllabus - Sharada Vikas Trust
... Semester: MBA II Author: Dr. Padma.V.Upadhyaya Syllabus Module 1 Unit 1 Introduction Basics of database systems, Traditional file approach, Motivation for database approach, The evolution of database systems, Database basics, ...
... Semester: MBA II Author: Dr. Padma.V.Upadhyaya Syllabus Module 1 Unit 1 Introduction Basics of database systems, Traditional file approach, Motivation for database approach, The evolution of database systems, Database basics, ...
Relation
... A referential integrity constraint can be displayed in a relational database schema as a directed arc from R1.FK to R2 A foreign key can refer to its own relation » e.g., the attribute SUPERSSN in EMPLOYEE refers to the supervisor of an employee ...
... A referential integrity constraint can be displayed in a relational database schema as a directed arc from R1.FK to R2 A foreign key can refer to its own relation » e.g., the attribute SUPERSSN in EMPLOYEE refers to the supervisor of an employee ...
here - The Smartpath Information Systems
... proposed by Edgar F. Codd, a pioneer of the relational model for databases, designed to define what is required from a database management system in order for it to be considered relational, i.e., a relational database management system (RDBMS)They are sometimes referred to as "Codd's Twelve Command ...
... proposed by Edgar F. Codd, a pioneer of the relational model for databases, designed to define what is required from a database management system in order for it to be considered relational, i.e., a relational database management system (RDBMS)They are sometimes referred to as "Codd's Twelve Command ...
Association - WordPress.com
... Assume that we know frequent itemsets of size k-1. Considering a k-itemset we can immediately conclude that by dropping two different items we have two frequent (k-1) itemsets. From another perspective this can be seen as a possible way to construct k-itemsets. We take two (k1) item sets which d ...
... Assume that we know frequent itemsets of size k-1. Considering a k-itemset we can immediately conclude that by dropping two different items we have two frequent (k-1) itemsets. From another perspective this can be seen as a possible way to construct k-itemsets. We take two (k1) item sets which d ...
Understanding Relational Database Concepts Professor Larry Heimann Carnegie Mellon University
... An Alternative: Relational Databases • Relational databases consist of a series of data tables linked together so that data can later be combined and extracted as needed. • Some terminology – table/ file – column / field – row / record ...
... An Alternative: Relational Databases • Relational databases consist of a series of data tables linked together so that data can later be combined and extracted as needed. • Some terminology – table/ file – column / field – row / record ...
comp426-f14-18-Databases
... • Next step is to identify attributes of those entities. • An attribute is labeled piece of information (i.e., a name/value pair) • In general, we expect every instance of a particular entity to have specific values for a set of common attributes. ...
... • Next step is to identify attributes of those entities. • An attribute is labeled piece of information (i.e., a name/value pair) • In general, we expect every instance of a particular entity to have specific values for a set of common attributes. ...
Chapter 17: Parallel Databases
... Pi,j computes the join of ri with sj. In order to do so, ri is replicated to Pi,0, Pi,1, ..., Pi,m-1, while si is replicated to P0,i, P1,i, ..., Pn-1,i Any join technique can be used at each processor Pi,j. ...
... Pi,j computes the join of ri with sj. In order to do so, ri is replicated to Pi,0, Pi,1, ..., Pi,m-1, while si is replicated to P0,i, P1,i, ..., Pn-1,i Any join technique can be used at each processor Pi,j. ...
SQL Tuning Training
... the entity. A set of related tables forms a database. A database is even managed and secured through tables (often referred to as user tables and system tables). ...
... the entity. A set of related tables forms a database. A database is even managed and secured through tables (often referred to as user tables and system tables). ...
Relation schema
... This is called a 4-tuple as it has 4 values A tuple (row) in the CUSTOMER relation. ...
... This is called a 4-tuple as it has 4 values A tuple (row) in the CUSTOMER relation. ...
Chapter 14: Query Optimization
... using information about foreign keys: V(customer-name, depositor) = 2500, and V(customer-name, customer) = 10000 The two estimates are 5000 * 10000/2500 = 20,000 and 5000 * ...
... using information about foreign keys: V(customer-name, depositor) = 2500, and V(customer-name, customer) = 10000 The two estimates are 5000 * 10000/2500 = 20,000 and 5000 * ...
Physical Design
... the PK and, where appropriate, AKs and FKs. a list of any derived attributes and how they should be computed; – referential integrity constraints for any FKs identified. ...
... the PK and, where appropriate, AKs and FKs. a list of any derived attributes and how they should be computed; – referential integrity constraints for any FKs identified. ...
