الشريحة 1
... Retrieval Queries in SQL (Cont.) •Basic form of the SQL SELECT statement is called a mapping or a SELECT-FROM-WHERE block SELECT
...
... Retrieval Queries in SQL (Cont.) •Basic form of the SQL SELECT statement is called a mapping or a SELECT-FROM-WHERE block SELECT
The Relational Theory
... – The rows of T1 are joined with the rows of T2 where the PK value in one table equals the FK value in the other table • Where column name are the same • Don’t use this in a Production Database – renaming causes ...
... – The rows of T1 are joined with the rows of T2 where the PK value in one table equals the FK value in the other table • Where column name are the same • Don’t use this in a Production Database – renaming causes ...
Prince Sultan University - CS 340 Introduction to Database Systems
... B. Database system concepts and architecture - Data models, schemas, and instances - Three-schema architecture and data independence - Database languages and interfaces - The database system environment - Centralized and client/server architectures for DBMSs - Classification of DBMSs C. Data modelin ...
... B. Database system concepts and architecture - Data models, schemas, and instances - Three-schema architecture and data independence - Database languages and interfaces - The database system environment - Centralized and client/server architectures for DBMSs - Classification of DBMSs C. Data modelin ...
The Relational Data Model Data and Its Structure Physical Data
... Manager) Manager < Employee)) Employee ) Why should constraint be in Employee an not Manager? Manager What if Employee is empty? ...
... Manager) Manager < Employee)) Employee ) Why should constraint be in Employee an not Manager? Manager What if Employee is empty? ...
Scalar Aggregation in FD-Inconsistent Databases
... the integrated database may be inconsistent with the constraints). The notion of a consistent query answer [2] attempts to reduce this tension by using constraints to qualify query answers. A consistent answer is, intuitively, true regardless of the way the database is fixed to remove constraint vio ...
... the integrated database may be inconsistent with the constraints). The notion of a consistent query answer [2] attempts to reduce this tension by using constraints to qualify query answers. A consistent answer is, intuitively, true regardless of the way the database is fixed to remove constraint vio ...
Connection con = DriverManager.getConnection( url, user, pass )
... a production system. It doesn’t scale well. • A better alternative is using a DataSource. • A DataSource offers connection pooling, where new connections are not thrown away but are instead set aside for the next time someone needs a connection. ...
... a production system. It doesn’t scale well. • A better alternative is using a DataSource. • A DataSource offers connection pooling, where new connections are not thrown away but are instead set aside for the next time someone needs a connection. ...
Database Management System - The Institute of Finance
... First, have we violated any FDs with our data? Because all SSNs are unique, there cannot be a FD violation of SSN → Name. Why? Because a FD X → Y says that given some value for X, you always get the same Y. Because the X's are unique, you will always get the same value. The same comment is true for ...
... First, have we violated any FDs with our data? Because all SSNs are unique, there cannot be a FD violation of SSN → Name. Why? Because a FD X → Y says that given some value for X, you always get the same Y. Because the X's are unique, you will always get the same value. The same comment is true for ...
Slides - Subbarao Kambhampati
... • They help in propagating constraints distributed across tables. • They help in predicting the attributes distribute across tables • They assist in completing the entity information by predicting the related attributes ...
... • They help in propagating constraints distributed across tables. • They help in predicting the attributes distribute across tables • They assist in completing the entity information by predicting the related attributes ...
CS263 lecture 11 & 12 - Computing
... Software which allows an application to interoperate with other software, without requiring the user to understand and code the low-level operations required to achieve interoperability With Synchronous systems, the requesting system waits for a response to the request in real time Asynchronous syst ...
... Software which allows an application to interoperate with other software, without requiring the user to understand and code the low-level operations required to achieve interoperability With Synchronous systems, the requesting system waits for a response to the request in real time Asynchronous syst ...
Appendix G: When is a DBMS Relational?
... well as data, and moreover that there is only one logical structure (relations) used to store system information. Rule 5—Comprehensive data sublanguage A relational system may support several languages and various modes of terminal use (for example, the fill-in-the-blanks mode). However, there must ...
... well as data, and moreover that there is only one logical structure (relations) used to store system information. Rule 5—Comprehensive data sublanguage A relational system may support several languages and various modes of terminal use (for example, the fill-in-the-blanks mode). However, there must ...
Grammar-like Functional Rules for Representing Query Optimization
... wrii be mterpreted by the query evaluator at run-tune LOLEPOPs are a vanatron of the relattonai aigrebra (e g , JOIN, UNION, etc ), supplemented wtth low-level operators such as ACCESS, SORT, SHIP, etc [FREY 871 Each LOLEPOP 1svtewed as a functton that operates on 1 or 2 tables*, whtch are parameter ...
... wrii be mterpreted by the query evaluator at run-tune LOLEPOPs are a vanatron of the relattonai aigrebra (e g , JOIN, UNION, etc ), supplemented wtth low-level operators such as ACCESS, SORT, SHIP, etc [FREY 871 Each LOLEPOP 1svtewed as a functton that operates on 1 or 2 tables*, whtch are parameter ...
Grammar-like Functional Rules for Representing Query Optimization
... wrii be mterpreted by the query evaluator at run-tune LOLEPOPs are a vanatron of the relattonai aigrebra (e g , JOIN, UNION, etc ), supplemented wtth low-level operators such as ACCESS, SORT, SHIP, etc [FREY 871 Each LOLEPOP 1svtewed as a functton that operates on 1 or 2 tables*, whtch are parameter ...
... wrii be mterpreted by the query evaluator at run-tune LOLEPOPs are a vanatron of the relattonai aigrebra (e g , JOIN, UNION, etc ), supplemented wtth low-level operators such as ACCESS, SORT, SHIP, etc [FREY 871 Each LOLEPOP 1svtewed as a functton that operates on 1 or 2 tables*, whtch are parameter ...
marked - Kansas State University
... Microsoft Access supports a variant of QBE called Graphical Query By Example (GQBE) GQBE differs from QBE in the following ways Attributes of relations are listed vertically, one below the other, instead of horizontally Instead of using variables, lines (links) between attributes are used to ...
... Microsoft Access supports a variant of QBE called Graphical Query By Example (GQBE) GQBE differs from QBE in the following ways Attributes of relations are listed vertically, one below the other, instead of horizontally Instead of using variables, lines (links) between attributes are used to ...
4a-SQL-Select
... SELECT statement • Save a query and give it a meaningful name if the query needs to be executed repeatedly. E.g. AllEmployeeEmail • A query can be viewed just like a table, but it’s just a real time snapshot of the table data. • Any update to the table will be reflected in the query. • Queries are ...
... SELECT statement • Save a query and give it a meaningful name if the query needs to be executed repeatedly. E.g. AllEmployeeEmail • A query can be viewed just like a table, but it’s just a real time snapshot of the table data. • Any update to the table will be reflected in the query. • Queries are ...
Formal Relational Query Languages
... Outer Join An extension of the join operation that avoids loss of information. Computes the join and then adds tuples form one relation that does not ...
... Outer Join An extension of the join operation that avoids loss of information. Computes the join and then adds tuples form one relation that does not ...
Venn Diagrams
... and if you fail to see that Supplier even once then consider that Supplier as part of the answer set. Then move on to a new Supplier. So instead of selecting members of the answer set looking at rows one at a time (which is what happens when we use join) we need to consider all the rows in Supplies ...
... and if you fail to see that Supplier even once then consider that Supplier as part of the answer set. Then move on to a new Supplier. So instead of selecting members of the answer set looking at rows one at a time (which is what happens when we use join) we need to consider all the rows in Supplies ...
On the performance of parallel join processing in shared nothing
... execution plan specifying the basic operators (e.g. scan, selection, join, etc.) to process the operation. The optimizer may support two types of intra-DML parallelism: inter- and intra-operator parallelism. Inter-operator parallelism refers to the concurrent execution of different operators in an e ...
... execution plan specifying the basic operators (e.g. scan, selection, join, etc.) to process the operation. The optimizer may support two types of intra-DML parallelism: inter- and intra-operator parallelism. Inter-operator parallelism refers to the concurrent execution of different operators in an e ...
Processing XML Data
... in the relational database. • Step 3: given a query Q in Xquery, translate it to a set of queries P over the relational database. • Step 4: translate the tuples returned from the relational database into XML elements. ...
... in the relational database. • Step 3: given a query Q in Xquery, translate it to a set of queries P over the relational database. • Step 4: translate the tuples returned from the relational database into XML elements. ...
Database design theory, Part I
... As we saw in the last segment, designing a good database is a non-trivial matter. The E/R model gives a useful “rapid prototyping” tool, but provides little guidance on “the best way” of doing things; we developed some best practices, based on observed bad behaviors we want to avoid, but it was an a ...
... As we saw in the last segment, designing a good database is a non-trivial matter. The E/R model gives a useful “rapid prototyping” tool, but provides little guidance on “the best way” of doing things; we developed some best practices, based on observed bad behaviors we want to avoid, but it was an a ...
Document
... Once database has been populated, users can query the data A data manipulation language controls how the user can specify queries, (and thus what types of queries are allowed) ...
... Once database has been populated, users can query the data A data manipulation language controls how the user can specify queries, (and thus what types of queries are allowed) ...
Introduction and the Relationship-Entity Model
... Once database has been populated, users can query the data A data manipulation language controls how the user can specify queries, (and thus what types of queries are allowed) ...
... Once database has been populated, users can query the data A data manipulation language controls how the user can specify queries, (and thus what types of queries are allowed) ...