KorthDB6_ch2
... Database System Concepts, 6th Ed. ©Silberschatz, Korth and Sudarshan See www.db-book.com for conditions on re-use ...
... Database System Concepts, 6th Ed. ©Silberschatz, Korth and Sudarshan See www.db-book.com for conditions on re-use ...
Database Systems - University of Texas at Dallas
... • NATURAL JOIN on two relations R and S – No join condition specified – Implicit EQUIJOIN condition for each pair of attributes with same name from R and S ...
... • NATURAL JOIN on two relations R and S – No join condition specified – Implicit EQUIJOIN condition for each pair of attributes with same name from R and S ...
slides
... Multi-relation access plans • Similar principle, but now many more possibilities to consider. • Common approach: – Consider subsets of the involved relations, and the conditions that apply to each subset. – Estimate the cost of evaluating the σπ×− expression restricted to this subset. – Need to dis ...
... Multi-relation access plans • Similar principle, but now many more possibilities to consider. • Common approach: – Consider subsets of the involved relations, and the conditions that apply to each subset. – Estimate the cost of evaluating the σπ×− expression restricted to this subset. – Need to dis ...
Applications of the Join Operation in the REA Data Model
... The self-join operation involves joining a table with the table itself. That is, a Cartesian product will be formed consisting of the combination of each record with all records of the same table. The selection of the records that takes place next is based on the data field(s) and the join condition ...
... The self-join operation involves joining a table with the table itself. That is, a Cartesian product will be formed consisting of the combination of each record with all records of the same table. The selection of the records that takes place next is based on the data field(s) and the join condition ...
Relation
... Possible violations for DELETE operation • DELETE may violate only referential integrity: • If the primary key value of the tuple being deleted is referenced from other tuples in the database • Can be remedied by several actions: RESTRICT, CASCADE, SET NULL (see Chapter 8 for more details) • RESTRI ...
... Possible violations for DELETE operation • DELETE may violate only referential integrity: • If the primary key value of the tuple being deleted is referenced from other tuples in the database • Can be remedied by several actions: RESTRICT, CASCADE, SET NULL (see Chapter 8 for more details) • RESTRI ...
ppt
... Can we check a database instance to see if an IC is violated ? Can we infer that an IC is true by looking at a database instance ? ...
... Can we check a database instance to see if an IC is violated ? Can we infer that an IC is true by looking at a database instance ? ...
IS 331-Spring 2017 - Information Systems
... gained by with actual database using industry-standard database management systems such as Oracle. Prerequisite: Completion IS218, Building Web Applications or IT202, Internet and Applications. It is also assumed that students have some basic familiarity with Microsoft Office (2007 or 2010), particu ...
... gained by with actual database using industry-standard database management systems such as Oracle. Prerequisite: Completion IS218, Building Web Applications or IT202, Internet and Applications. It is also assumed that students have some basic familiarity with Microsoft Office (2007 or 2010), particu ...
location-query
... The value of the dynamic attribute at time A.update_time + t0 is A.update_value + A.function( t0 ) The location attribute has sub-attributes L.x, L.y, L.speed, and L.angle or L.route, where x and y are of type A Only when there is a change in speed or change in direction of the object, the database ...
... The value of the dynamic attribute at time A.update_time + t0 is A.update_value + A.function( t0 ) The location attribute has sub-attributes L.x, L.y, L.speed, and L.angle or L.route, where x and y are of type A Only when there is a change in speed or change in direction of the object, the database ...
A column alias is a new heading/title for a column
... The concatenation operator can link columns to other columns, arithmetic expressions, or constant values to create a character expression. Columns on either side of the operator are combined to make a single output column. 35. What is a literal value and what are literal values enclosed by? A litera ...
... The concatenation operator can link columns to other columns, arithmetic expressions, or constant values to create a character expression. Columns on either side of the operator are combined to make a single output column. 35. What is a literal value and what are literal values enclosed by? A litera ...
ICS324 Database Systems - Syllabus
... Basic database concepts. Conceptual modeling. Relational data model. Relational theory and languages. Database Design. Introduction to query processing and optimization. Introduction to concurrency and recovery. ...
... Basic database concepts. Conceptual modeling. Relational data model. Relational theory and languages. Database Design. Introduction to query processing and optimization. Introduction to concurrency and recovery. ...
r – s
... of the following: A relation in the database A constant relation Let E1 and E2 be relational-algebra expressions; the following are ...
... of the following: A relation in the database A constant relation Let E1 and E2 be relational-algebra expressions; the following are ...
Databases
... in: IT technology: Databases. The test takes the form of a set take-home assignment to be handed in after 3 days, in which the student completes a designated task on data modelling, SQL, and modelling and search tools, thus documenting his/her command of the techniques covered in the course. A grade ...
... in: IT technology: Databases. The test takes the form of a set take-home assignment to be handed in after 3 days, in which the student completes a designated task on data modelling, SQL, and modelling and search tools, thus documenting his/her command of the techniques covered in the course. A grade ...
Nov-30-information-e..
... Today, Microsoft claims to "love" the opensource concept, by which software code is made public to encourage improvement and development by outside programmers. Gates himself says Microsoft will gladly disclose its crown jewels--the coveted code behind the Windows operating system--to select custome ...
... Today, Microsoft claims to "love" the opensource concept, by which software code is made public to encourage improvement and development by outside programmers. Gates himself says Microsoft will gladly disclose its crown jewels--the coveted code behind the Windows operating system--to select custome ...
computing candidate keys of relational operators for optimizing
... A large portion of data generated and stored by scientific databases, data warehouses, and workflow management systems is not entered manually by a user, but is derived from existing data using complex transformations. Understanding the semantics of such data and estimating its quality is not possib ...
... A large portion of data generated and stored by scientific databases, data warehouses, and workflow management systems is not entered manually by a user, but is derived from existing data using complex transformations. Understanding the semantics of such data and estimating its quality is not possib ...
Conceptual Data Models for Database Design
... The entity type describes the intension, or schema for a set of entities that share the same structure. The collection of entities of a particular entity type is grouped into the entity set, called the extension. Key Attributes of an Entity Type An important constraint on entities of an entity typ ...
... The entity type describes the intension, or schema for a set of entities that share the same structure. The collection of entities of a particular entity type is grouped into the entity set, called the extension. Key Attributes of an Entity Type An important constraint on entities of an entity typ ...
Lecture note 6
... DBMS does not allow illegal instances. 9 If the DBMS checks ICs, stored data is more faithful to realworld meaning, that is, for consistency and accuracy. 9 When ICs are enforced, DBMS also avoids data entry errors. Remarks: 9 For relational (and object-oriented) databases, domain constraints are a ...
... DBMS does not allow illegal instances. 9 If the DBMS checks ICs, stored data is more faithful to realworld meaning, that is, for consistency and accuracy. 9 When ICs are enforced, DBMS also avoids data entry errors. Remarks: 9 For relational (and object-oriented) databases, domain constraints are a ...
bipin-mobile-presentation
... DBMS because it handles multi-user access which is an inherent property. A Wrapper application shall be used on DBMS, because normal DBMS do not have spatio-temporal query handling capabilities. Because the mobile device have movement involved, updations to the location data is web enabled, a se ...
... DBMS because it handles multi-user access which is an inherent property. A Wrapper application shall be used on DBMS, because normal DBMS do not have spatio-temporal query handling capabilities. Because the mobile device have movement involved, updations to the location data is web enabled, a se ...
Slide: Temporal Databases
... tuples be semantically independent of one another. By definition, a relation is a set; hence, its elements (tuples) must be independent of one another. In an unnormalized TVR, every tuple has incomplete information about the lifespan of its attributes; therefore, it becomes dependent on other tuples ...
... tuples be semantically independent of one another. By definition, a relation is a set; hence, its elements (tuples) must be independent of one another. In an unnormalized TVR, every tuple has incomplete information about the lifespan of its attributes; therefore, it becomes dependent on other tuples ...
Towards Building Robust Natural Language Interfaces to Databases
... that had recently taken an introductory relational database course. The subjects were instructed to read the user’s manual of our administration tool and were trained on its use. The training examples were over several mocked up canonical examples and were in no way related to the Geoquery 250 corpu ...
... that had recently taken an introductory relational database course. The subjects were instructed to read the user’s manual of our administration tool and were trained on its use. The training examples were over several mocked up canonical examples and were in no way related to the Geoquery 250 corpu ...
designing database(updated)
... The procedure for representing relationships depends on both the degree of the relationship – unary, binary, ternary – and the cardinalities of the relationship. Binary 1:N Relationship: is represented by adding the primary key attribute (or attributes) of the entity on the one side of the relations ...
... The procedure for representing relationships depends on both the degree of the relationship – unary, binary, ternary – and the cardinalities of the relationship. Binary 1:N Relationship: is represented by adding the primary key attribute (or attributes) of the entity on the one side of the relations ...
MayBMS: A System for Managing Large Uncertain and Probabilistic Databases.
... Central themes in our research include the creation of foundations of query languages for probabilistic databases by developing analogs of relational algebra [22, 21] and SQL [6, 8] and the development of efficient query processing techniques [5, 25, 3, 23, 24, 17]. In practice, the efficient evalua ...
... Central themes in our research include the creation of foundations of query languages for probabilistic databases by developing analogs of relational algebra [22, 21] and SQL [6, 8] and the development of efficient query processing techniques [5, 25, 3, 23, 24, 17]. In practice, the efficient evalua ...