Chương 1. DATA DICTIONARY, VIEWS VÀ PACKAGES
1.1.DATA DICTIONARY VÀ VIEWS
1.1.1. Data Dictionary
Data dictionary hay từ điển dữ liệu hệ thống là phần rất quan trọng trong Oracle database. Đó là một tập hợp các table và các view sử dụng cho việc tham chiếu đến các thông tin liên quan tới database. Data dictionary được tạo bởi file script sql.bsq trong quá trình tạo database. Data dictionary bao gồm các thông tin trung tâm của Oracle server.
CHAPTER 1 Relational Database Systems and Oracle
CHAPTER 2 Introduction to SQL, iSQL*Plus, and SQL*Plus
CHAPTER 3 Data Definition, Part I
CHAPTER 4 Retrieval: The Basics
CHAPTER 5 Retrieval: Functions
CHAPTER 6 Data Manipulation
CHAPTER 7 Data Definition, Part II
Chapter 1: Relational Database Systems and Oracle
Chapter 2: Introduction to SQL, AQL*Plus, and SQL Developer
Chapter 3: Data Definition, Part I
Chapter 4: Retrieval: The Basics
Chapter 5: Retrieval: Functions
Chapter 6: Data Manipulation
Chapter 7: Data Definition, Part II
Chapter 8: Retrieval: Multiple Tables and Aggregation
Chapter 9: Retrieval: Some Advanced Features
Fox et al. (1998) carried out a logistic regression analysis with discrete covariates in
which one of the covariates was missing for a substantial percentage of respondents. The
missing data problem was addressed using the “approximate Bayesian bootstrap.” We return to
this missing data problem to provide a form of case study. Using the Fox et al. (1998) data for
expository purposes we carry out a comparative analysis of eight of the most commonly used
techniques for dealing with missing data. We then report on two sets of simulations based on
the original data....
Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Critical Care giúp cho các bạn có thêm kiến thức về y học đề tài: Training in data definitions improves quality of intensive care data...
Database Management Systems: Chapter 0 - An Overview of a Database Management System includes about What is a DBMS? DBMS Capabilities, Data-Definition Language Commands, Answering the query, Buffer manager, Transaction processor’s tasks.
This module describes how to create and use Microsoft XML schemas to
validate XML documents. Students have already been introduced to the concept
of validation in Module 2, ìOverview of XML Technologies.î In that module,
we introduced the need for validation, showed the syntax of simple Document
Type Definitions (DTDs), and briefly mentioned the use of XML schemas as
the preferred alternative to DTDs.
The Definitive Guide to the Microsoft Enterprise Library introduces one of the most exciting and popular .NET–oriented initiatives, the Enterprise Library. The EL offers eight application blocks and other reusable code that are used to solve a variety of common problem spaces. These problems cover a number of topics, including data access, exception handling, caching, logging, security, cryptography, validation, policy injection and configuration.
We live in the data age. It’s not easy to measure the total volume of data stored electronically,
but an IDC estimate put the size of the “digital universe” at 0.18 zettabytes
in 2006 and is forecasting a tenfold growth by 2011 to 1.8 zettabytes.1 A zettabyte is
1021 bytes, or equivalently one thousand exabytes, one million petabytes, or one billion
terabytes. That’s roughly the same order of magnitude as one disk drive for every person
in the world.
What could you do with data if scalability wasn't a problem? With this hands-on guide, you'll learn how Apache Cassandra handles hundreds of terabytes of data while remaining highly available across multiple data centers -- capabilities that have attracted Facebook, Twitter, and other data-intensive companies. Cassandra: The Definitive Guide provides the technical details and practical examples you need to assess this database management system and put it to work in a production environment
In a communication system, data are propagated from one point to another by means of
electromagnetic signals. A signal is a series of analogue or digital data. That is a varying voltage
(either continuous or discrete) with time in an electronic communication system.
Definitions of Data and Signals:
Analog Data - Data represented by a continuous physical quantity whose magnitude is proportion
a suitable function of the data (information). It can have more than two discrete values in
contrast to digital data. ...
MySQL 5 is slated to be the most significant release in the products history. The Definitive Guide to MySQL 5, Third Edition is the newest revision of Michael Koflers popular book. This is the first book to offer in-depth instruction about the new features of the world's most popular open source database server. Updated to reflect changes in MySQL version 5, this book will expose you to MySQL's impressive array of new features: views, stored procedures, triggers, and spatial data types.
What are your organization’s policies for generating and using huge datasets full of personal information? This book examines ethical questions raised by the big data phenomenon, and explains why enterprises need to reconsider business decisions concerning privacy and identity. Authors Kord Davis and Doug Patterson provide methods and techniques to help your business engage in a transparent and productive ethical inquiry into your current data practices.
The relational Model of Data is based on the concept of a Relation.
A Relation is a mathematical concept based on the ideas of sets.
The strength of the relational approach to data management comes from the formal foundation provided by the theory of relations.
We review the essentials of the relational approach in this chapter.
In a recent paper by H. L. Resnikoff and J. L. Dolby, "The Nature of Affixing in Written English," an algorithm for the structural definition of affixes was developed and applied to data consisting of all the words of the form CVCVC in the Shorter Oxford Dictionary.
After studying this chapter, you should be able to: Explain the importance and advantages of databases, as well as the difference between database systems and file-based legacy systems; explain the difference between logical and physical views of a database; explain fundamental concepts of database systems such as DBMS, schemas, the data dictionary, and DBMS languages;...
Corpus-based sense disambiguation methods, like most other statistical NLP approaches, suffer from the problem of data sparseness. In this paper, we describe an approach which overcomes this problem using dictionary definitions. Using the definitionbased conceptual co-occurrence data collected from the relatively small Brown corpus, our sense disambiguation system achieves an average accuracy comparable to human performance given the same contextual information.
A new type of machine dictionary is described, which uses terminological relations to build up a semantic network representing the terms of a particular subject field, through interaction with the user. These relations are then used to dynamically generate outline definitions of terms in on-line query mode. The definitions produced are precise, consistent and informative, and allow the user to situate a query term in the local conceptual ~vironment.
Chapter 8 introduce SQL - Schema definition, basic constraints, and queries. The main contents in this chapter: Create database, create table, attribute data types and domains in SQL, data integrity (toàn vẹn dữ liệu), declarative integrity,...