IT420 Spring 2007 6-week Exam Review Sheet Introduction to databases
... • Specify primary key • Specify candidate (alternate keys) • Specify properties for each column 1. data type 2. null /not null 3. default values 4. other constraints b. Transform relationships (foreign keys used here) • 1:1 relationships, 1:N relationships - identifying relationships - non-identifyi ...
... • Specify primary key • Specify candidate (alternate keys) • Specify properties for each column 1. data type 2. null /not null 3. default values 4. other constraints b. Transform relationships (foreign keys used here) • 1:1 relationships, 1:N relationships - identifying relationships - non-identifyi ...
A Coq Formalization of the Relational Data Model
... form, we provide both a formal specification and a certified version of the algorithm that translates relational algebra queries into conjunctive queries. We then present logical query optimization, for both query formalisms, and prove the main “databases theorems”: algebraic equivalences, the homom ...
... form, we provide both a formal specification and a certified version of the algorithm that translates relational algebra queries into conjunctive queries. We then present logical query optimization, for both query formalisms, and prove the main “databases theorems”: algebraic equivalences, the homom ...
DBXplorer : A System For Keyword-Based Search Over Relational
... Example for Keyword-Based Search is searching for “Jim Gary” on Microsoft intranet to obtain matched rows, i.e., rows in DB where ‘Jim Gary’ occur. ...
... Example for Keyword-Based Search is searching for “Jim Gary” on Microsoft intranet to obtain matched rows, i.e., rows in DB where ‘Jim Gary’ occur. ...
LISP Project 3
... army smith is not such a liberated woman that she does not take on her husbands name. Thus one must also store an entry for jones in the data base whose property values are identical to those of smith. jones must also be inserted into the colonel set. Once this is done, smith is deleteofficer’d from ...
... army smith is not such a liberated woman that she does not take on her husbands name. Thus one must also store an entry for jones in the data base whose property values are identical to those of smith. jones must also be inserted into the colonel set. Once this is done, smith is deleteofficer’d from ...
Introduction to database design
... Algorithm for evaluating a SELECT-FROM-WHERE: 1. FROM: Cartesian product of tables is computed. Subqueries are computed recursively. 2. WHERE: Rows not fulfilling condition are deleted. Note that aggregation is evaluated after WHERE, i.e. aggregate values can’t be in the condition. 3. GROUP BY: T ...
... Algorithm for evaluating a SELECT-FROM-WHERE: 1. FROM: Cartesian product of tables is computed. Subqueries are computed recursively. 2. WHERE: Rows not fulfilling condition are deleted. Note that aggregation is evaluated after WHERE, i.e. aggregate values can’t be in the condition. 3. GROUP BY: T ...
Limitations of the relational model
... what does it mean must comply with? what is the logical model? must be deduced from the DB? the DB must be consistent with them?must be true of the DB? ...
... what does it mean must comply with? what is the logical model? must be deduced from the DB? the DB must be consistent with them?must be true of the DB? ...
Intranet Mediator
... • Necessary and sufficient conditions that the least distance database is in fact a correct database to answer the given query • Mapping from natural language query to a relational query or a keyword based query • Automatic construction of ontology • Multiple databases, including text databases, nec ...
... • Necessary and sufficient conditions that the least distance database is in fact a correct database to answer the given query • Mapping from natural language query to a relational query or a keyword based query • Automatic construction of ontology • Multiple databases, including text databases, nec ...
SQL Overview - WordPress.com
... When you are executing an SQL command for any RDBMS, the system determines the best way to carry out your request and SQL engine figures out how to interpret the task. There are various components included in the process. These components are Query Dispatcher, Optimization Engines, Classic Query Eng ...
... When you are executing an SQL command for any RDBMS, the system determines the best way to carry out your request and SQL engine figures out how to interpret the task. There are various components included in the process. These components are Query Dispatcher, Optimization Engines, Classic Query Eng ...
Introduction to Structured Query Language
... Select partial table contents by placing restrictions on rows to be included in output – Add conditional restrictions to the SELECT statement, using WHERE clause ...
... Select partial table contents by placing restrictions on rows to be included in output – Add conditional restrictions to the SELECT statement, using WHERE clause ...
Relational Data Model
... Composed of a set of tables called relations Records (rows) in the table are called tuples Fields (columns) in the table are called domains We will use the terms tables, records, and fields ...
... Composed of a set of tables called relations Records (rows) in the table are called tuples Fields (columns) in the table are called domains We will use the terms tables, records, and fields ...
A Probabilistic Relational Algebra for the Integration of Information
... argument relation(s). A similar model based on Dempster-Shafer theory with extensional semantics is proposed by Lee [1992]. Both approaches suffer from the fact that the result coincides with the underlying theory for simple relational expressions only. As a simple example, consider a query asking f ...
... argument relation(s). A similar model based on Dempster-Shafer theory with extensional semantics is proposed by Lee [1992]. Both approaches suffer from the fact that the result coincides with the underlying theory for simple relational expressions only. As a simple example, consider a query asking f ...
ppt
... Algorithm A1 (linear search). Scan each file block and test all records to see whether they satisfy the selection condition. Cost estimate = br block transfers + 1 seek br denotes number of blocks containing records from relation r ...
... Algorithm A1 (linear search). Scan each file block and test all records to see whether they satisfy the selection condition. Cost estimate = br block transfers + 1 seek br denotes number of blocks containing records from relation r ...
All questions carry equal marks
... Discuss the mechanism used to read data from or write data into the disk. Explain how the double buffering improves the block access time. ...
... Discuss the mechanism used to read data from or write data into the disk. Explain how the double buffering improves the block access time. ...
cmps3420_database_systems
... 3c. An ability to design, implement and evaluate a computer-based system, process, component, or program to meet desired needs. 3f. An ability to communicate effectively with a range of audiences. 3h. Recognition of the need for and an ability to engage in continuing professional development. 3i. An ...
... 3c. An ability to design, implement and evaluate a computer-based system, process, component, or program to meet desired needs. 3f. An ability to communicate effectively with a range of audiences. 3h. Recognition of the need for and an ability to engage in continuing professional development. 3i. An ...
361-001_Huen.pdf
... 1. it is not handed in by the final due date, or 2. it is not a reasonable attempt to solve the assigned problem The course grade will be reduced by three letter grades (e.g. C to F) if you hand in a program which is not your own work or your team’s work if you choose to form a twoperson team. An as ...
... 1. it is not handed in by the final due date, or 2. it is not a reasonable attempt to solve the assigned problem The course grade will be reduced by three letter grades (e.g. C to F) if you hand in a program which is not your own work or your team’s work if you choose to form a twoperson team. An as ...
Assignment Front Sheet- South Nottingham College Learner name
... Mia’s sandwich shop has just expanded due to popular demand. She is planning to open a further three shops. The shops’ proprietor Mia Baggio has decided that in order for her business to expand further a computerised system is required to manage all the shops’ orders. She has heard something about d ...
... Mia’s sandwich shop has just expanded due to popular demand. She is planning to open a further three shops. The shops’ proprietor Mia Baggio has decided that in order for her business to expand further a computerised system is required to manage all the shops’ orders. She has heard something about d ...
Ensuring transaction integrity
... Remember: Inner Selects (also called sub-selects or sub-queries) are fullbodied SQL Select statements: Therefore, they can, when required to do so, return more than a single value (one tuple, one attribute) relation. Example: List employees who earn the maximum salary in each of the departments. sel ...
... Remember: Inner Selects (also called sub-selects or sub-queries) are fullbodied SQL Select statements: Therefore, they can, when required to do so, return more than a single value (one tuple, one attribute) relation. Example: List employees who earn the maximum salary in each of the departments. sel ...
Seminar 5: OO Database Design
... Relationships are implemented using foreign keys. See arrows ( ) from foreign keys to the primary keys. Many-to-many relationships are implemented as a linking relation using primary keys of participating relations (see WORKS_ON relation). The real-world concept that an instance of one entity is as ...
... Relationships are implemented using foreign keys. See arrows ( ) from foreign keys to the primary keys. Many-to-many relationships are implemented as a linking relation using primary keys of participating relations (see WORKS_ON relation). The real-world concept that an instance of one entity is as ...
Escape from the Data Warehouse Death March
... • But--the Oracle optimizer has some “tricks” to use when joining tables in Star Schemas. • These two tricks are called “Star Join” and “Star Transformation.” • These two methods are NOT the same, and use drastically different ideas. ...
... • But--the Oracle optimizer has some “tricks” to use when joining tables in Star Schemas. • These two tricks are called “Star Join” and “Star Transformation.” • These two methods are NOT the same, and use drastically different ideas. ...
Multi-Relational Data Mining using Probabilistic Models Research
... , which is the key of a tuple in the appropriate range type. For each tuple in to denote the value of the instance and each of its attributes , we use in . A relational skeleton of a relational schema is a partial specification of an for each table and instance of the schema. It specifies the set of ...
... , which is the key of a tuple in the appropriate range type. For each tuple in to denote the value of the instance and each of its attributes , we use in . A relational skeleton of a relational schema is a partial specification of an for each table and instance of the schema. It specifies the set of ...