9/4 - Penn Engineering - University of Pennsylvania
... How do we stop two people changing the file at the same time and leaving it in a physical (or logical) mess? Suppose the system crashes while we are changing the calendar. How do we recover our work? ...
... How do we stop two people changing the file at the same time and leaving it in a physical (or logical) mess? Suppose the system crashes while we are changing the calendar. How do we recover our work? ...
Database Normalization
... OLTP Applications are characterized by a high volume of small transactions such as updating a sales record at a super market checkout counter. The expectation is that each transaction will leave the database in a consistent state. By contrast, databases intended for OLAP operations are primarily "re ...
... OLTP Applications are characterized by a high volume of small transactions such as updating a sales record at a super market checkout counter. The expectation is that each transaction will leave the database in a consistent state. By contrast, databases intended for OLAP operations are primarily "re ...
Chapter 10
... – If transaction committed after last checkpoint • DBMS redoes the transaction using “after” values ...
... – If transaction committed after last checkpoint • DBMS redoes the transaction using “after” values ...
OVERCOMING RELATIONAL DATABASE LIMITATIONS WITH NOSQL
... 1. Key-value: As the name suggests, these databases are intended to store key-value pairs. Key-value databases are designed to be fast, trading durability for raw speed1. While in traditional key-value data structures a string key is associated with a string value, in a key-value database, the valu ...
... 1. Key-value: As the name suggests, these databases are intended to store key-value pairs. Key-value databases are designed to be fast, trading durability for raw speed1. While in traditional key-value data structures a string key is associated with a string value, in a key-value database, the valu ...
NoSQL DATABASE - COW :: Ceng - Middle East Technical University
... Any number of fields can be added Multiple types of documents (objects) and nested documents or lists ...
... Any number of fields can be added Multiple types of documents (objects) and nested documents or lists ...
Slide 1
... • Before & after images for updates allows detailed change analysis • Log purging and archiving • Multi-version metadata and DDF management ...
... • Before & after images for updates allows detailed change analysis • Log purging and archiving • Multi-version metadata and DDF management ...
File - Mr. Lawson`s
... Primary Key: This will be the unique field for each record. The VIN will be the primary key as each car will have a unique VIN. (select one if asked on exam) ...
... Primary Key: This will be the unique field for each record. The VIN will be the primary key as each car will have a unique VIN. (select one if asked on exam) ...
What is Exadata?
... Moving an existing application to Exadata •Try these options and see which is faster: •Indexes visible or invisible •optimizer_index_cost_adj normal (100) or high (> 100) •CELL_OFFLOAD_PROCESSING=FALSE or TRUE •All of these options can be tested without changing the application ...
... Moving an existing application to Exadata •Try these options and see which is faster: •Indexes visible or invisible •optimizer_index_cost_adj normal (100) or high (> 100) •CELL_OFFLOAD_PROCESSING=FALSE or TRUE •All of these options can be tested without changing the application ...
Data Integrity
... Data integrity is a fundamental component of information security. In its broadest use, “data integrity” refers to the accuracy, reliability and consistency of data stored over its entire life-cycle in a database, data warehouse, data mart or other construct. The term – Data Integrity - can be use ...
... Data integrity is a fundamental component of information security. In its broadest use, “data integrity” refers to the accuracy, reliability and consistency of data stored over its entire life-cycle in a database, data warehouse, data mart or other construct. The term – Data Integrity - can be use ...
Cassandra - GeoPense
... effectively and consistently allows everyday information to be stored and retrieved by computer. The basic entity in a relational database is the table. Tables store information such as inventory items, customers, suppliers, addresses, orders, etc. These tables are then related to each other by one ...
... effectively and consistently allows everyday information to be stored and retrieved by computer. The basic entity in a relational database is the table. Tables store information such as inventory items, customers, suppliers, addresses, orders, etc. These tables are then related to each other by one ...
Entities and Attributes
... Introduction to Database Modeling The great thing is relational databases aren't new. They've been around since the '70s. So you're coming in at a time when the methods for modeling a database have been battle tested over four decades. We know what works and what doesn't. And to design a good datab ...
... Introduction to Database Modeling The great thing is relational databases aren't new. They've been around since the '70s. So you're coming in at a time when the methods for modeling a database have been battle tested over four decades. We know what works and what doesn't. And to design a good datab ...
Accounting Information Systems: Essential Concepts
... Shared Data Ownership - all data within a database are owned in common by the users. The portion of the database that is of interest to each user is known as the sub-schema Centralized Data Management - the database management system stands guard over the database and presents the logical view to ...
... Shared Data Ownership - all data within a database are owned in common by the users. The portion of the database that is of interest to each user is known as the sub-schema Centralized Data Management - the database management system stands guard over the database and presents the logical view to ...
Visual Basic Database Access
... • Connection Object: Represent a connection to the database. • Command Object: The command object allows us to execute a SQL statement or a stored procedure. • DataReader: It is a read-only and forward-only pointer into a table to retrieve records. • DataSet Object: A DataSet object can hold several ...
... • Connection Object: Represent a connection to the database. • Command Object: The command object allows us to execute a SQL statement or a stored procedure. • DataReader: It is a read-only and forward-only pointer into a table to retrieve records. • DataSet Object: A DataSet object can hold several ...
Transactions
... application (same as copy value into program variable) Write: bring object into main memory from disk and modify it. Write it back to disk (might be done sometime later) ...
... application (same as copy value into program variable) Write: bring object into main memory from disk and modify it. Write it back to disk (might be done sometime later) ...
Chapter 12 Exercises and Answers
... What formula is stored in F15? SUM(F4..F14) D16 contains the formula D15/COUNT(D4..D14). What is another formula that would yield the same value? AVERAGE(D4..D14) Which formula is stored in E13? There isn't a formula stored there; it is a single value. What values in what cells would change if Phil' ...
... What formula is stored in F15? SUM(F4..F14) D16 contains the formula D15/COUNT(D4..D14). What is another formula that would yield the same value? AVERAGE(D4..D14) Which formula is stored in E13? There isn't a formula stored there; it is a single value. What values in what cells would change if Phil' ...
Distributed Transactions
... Most of the information systems used in businesses are transaction based. The market for transaction processing is many tens of billions of dollars per year Not long ago, transaction processing was only used in large ...
... Most of the information systems used in businesses are transaction based. The market for transaction processing is many tens of billions of dollars per year Not long ago, transaction processing was only used in large ...
primary key - WordPress.com
... Choosing Not to Use BCNF BCNF is used to control anomalies from functional dependencies There are times when BCNF is not desirable The classic example is ZIP codes: ...
... Choosing Not to Use BCNF BCNF is used to control anomalies from functional dependencies There are times when BCNF is not desirable The classic example is ZIP codes: ...
The History of Databases
... machine representation purposes. Accordingly, it provides a basis for a high level data language which will yield maximal independence between programs on the one hand and machine representation on the other.”(Codd 1970) ...
... machine representation purposes. Accordingly, it provides a basis for a high level data language which will yield maximal independence between programs on the one hand and machine representation on the other.”(Codd 1970) ...
Logical Data Modelling
... Data Access • Data is retrieved by reference to name (of an Attribute) & value (held in a Data Cell) only. • Most important Attribute(s) is know as the ‘Key’, of which there are two types. – Primary Key: • special Attribute(s) used to control access to Tuples (i.e. rows) of data. ...
... Data Access • Data is retrieved by reference to name (of an Attribute) & value (held in a Data Cell) only. • Most important Attribute(s) is know as the ‘Key’, of which there are two types. – Primary Key: • special Attribute(s) used to control access to Tuples (i.e. rows) of data. ...
Introduction to Database Systems
... Each application must move large datasets between main memory and secondary storage (must deal with, e.g., buffering, page-oriented access, etc.) Each application must deal with some method of identifying all data items in case the available addressing mode is not sufficient (e.g., 32-bit addressing ...
... Each application must move large datasets between main memory and secondary storage (must deal with, e.g., buffering, page-oriented access, etc.) Each application must deal with some method of identifying all data items in case the available addressing mode is not sufficient (e.g., 32-bit addressing ...