The document summarizes key concepts related to database systems, including data models, schemas, instances, DBMS architecture, languages, interfaces, environment, and classification of DBMSs. It defines data models as concepts to describe database structure and constraints. The three-schema architecture supports data independence through conceptual, internal, and external schemas. Database languages include DDL for schema definition and DML for data manipulation. DBMS interfaces provide access for different types of users.
Database concepts and Archeticture Ch2 with in class ActivitiesZainab Almugbel
This is the slides of chapter 2 of the book Ramez Elmasri and Shamkant Navathe, "Fundamentals of Database Systems" 6th Edition, 2010
I did not include the activities in the slides. I printed them out in separate papers. Then, I asked students: who liked to participate in activity 1 (the interview) in the class. I selected 2 students for the first activity (one was the interviewer and another was the guest). I did the same for the other activities.
● Distributed Database Management Systems Advantages and Disadvantages.
● Characteristics of Distributed Database Management Systems.
● Levels of Data and Process Distribution.
● Distributed Database Transparency Features.
● Transaction Performance and Failure Transparency.
Database concepts and Archeticture Ch2 with in class ActivitiesZainab Almugbel
This is the slides of chapter 2 of the book Ramez Elmasri and Shamkant Navathe, "Fundamentals of Database Systems" 6th Edition, 2010
I did not include the activities in the slides. I printed them out in separate papers. Then, I asked students: who liked to participate in activity 1 (the interview) in the class. I selected 2 students for the first activity (one was the interviewer and another was the guest). I did the same for the other activities.
● Distributed Database Management Systems Advantages and Disadvantages.
● Characteristics of Distributed Database Management Systems.
● Levels of Data and Process Distribution.
● Distributed Database Transparency Features.
● Transaction Performance and Failure Transparency.
ADVANCE DATABASE MANAGEMENT SYSTEM CONCEPTS & ARCHITECTURE by vikas jagtapVikas Jagtap
The data that indicates the earth location (latitude & longitude, or height & depth ) of these rendered objects is known as spatial data.
When the map is rendered, objects of this spatial data are used to project the location of the objects on 2-Dimentional piece of paper.
The spatial data management systems are designed to make the storage, retrieval, & manipulation of spatial data (i.e points, lines and polygons) easier and natural to users, such as GIS.
While typical databases can understand various numeric and character types of data, additional functionality needs to be added for databases to process spatial data types.
These are typically called geometry or feature.
1. introduction
2. data
3. dbms
4.uses of dbms
5. purpose of dbms
6. types of dbms
7. er-model
8. how to build a dbms
9.description of table in dbms
10. terminology in a dbms
11. advantages
12. disadvantages
Detailed comparison of two common legacy databases - HP's SQL/MP running on the NonStop Guardian environment and IBM's DB2 running on its z/OS platform, comparing a range of functionalities.
SQL is a standard language for accessing and manipulating databases.
*What is SQL?
SQL stands for Structured Query Language
SQL lets you access and manipulate databases
SQL is an ANSI (American National Standards Institute) standard
*What Can SQL do?
SQL can execute queries against a database
SQL can retrieve data from a database
SQL can insert records in a database
SQL can update records in a database
SQL can delete records from a database
SQL can create new databases
SQL can create new tables in a database
ADVANCE DATABASE MANAGEMENT SYSTEM CONCEPTS & ARCHITECTURE by vikas jagtapVikas Jagtap
The data that indicates the earth location (latitude & longitude, or height & depth ) of these rendered objects is known as spatial data.
When the map is rendered, objects of this spatial data are used to project the location of the objects on 2-Dimentional piece of paper.
The spatial data management systems are designed to make the storage, retrieval, & manipulation of spatial data (i.e points, lines and polygons) easier and natural to users, such as GIS.
While typical databases can understand various numeric and character types of data, additional functionality needs to be added for databases to process spatial data types.
These are typically called geometry or feature.
1. introduction
2. data
3. dbms
4.uses of dbms
5. purpose of dbms
6. types of dbms
7. er-model
8. how to build a dbms
9.description of table in dbms
10. terminology in a dbms
11. advantages
12. disadvantages
Detailed comparison of two common legacy databases - HP's SQL/MP running on the NonStop Guardian environment and IBM's DB2 running on its z/OS platform, comparing a range of functionalities.
SQL is a standard language for accessing and manipulating databases.
*What is SQL?
SQL stands for Structured Query Language
SQL lets you access and manipulate databases
SQL is an ANSI (American National Standards Institute) standard
*What Can SQL do?
SQL can execute queries against a database
SQL can retrieve data from a database
SQL can insert records in a database
SQL can update records in a database
SQL can delete records from a database
SQL can create new databases
SQL can create new tables in a database
Fundamentals of database system - Database System Concepts and ArchitectureMustafa Kamel Mohammadi
In this chapter you will learn
DBMS evolution
Data model
Three schema architecture
DBMS language
DBMS interfaces
DBMS components
Classification of DBMS
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The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
The Art Pastor's Guide to Sabbath | Steve ThomasonSteve Thomason
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Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
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2. Database System Concepts and Architecture
2.1 Data Models, Schemas, and Instances
2.2 DBMS Architecture and Data Independence
2.3 Database Languages and Interfaces
2.4 The Database System Environment
2.5 Classification of Database Management Systems
2.6 Summary
2-1 2
3. 2.1 Data Models, Schemas, and Instances
‧data types
‧relationships
Data Model: A set of concepts to describe the structure of a
database, and certain constraints that the database should obey.
Provide data abstraction
Data Model Operations: Operations for specifying database
retrievals and updates by referring to the concepts of the data
model.
‧generic operation: insert, delete, modify, retrieve
‧user-defined operations
2-2 3
4. 2.1.1 Categories of Data Models:
- Conceptual (high-level, semantic) data models: Provide concepts that
are close to the way many users perceive data.
(Also called entity-based or object-based data models.)
‧entity ‧attribute ‧relationship
- Physical (low-level, internal) data models: Provide concepts that
describe details of how data is stored in the computer.
‧record formats ‧record ordering ‧access paths
- Implementation (record-oriented) data models: Provide concepts that
fall between the above two, balancing user views with some computer
storage details.
‧relational ‧network ‧hierarchical
2-2 4
5. 2.1.2 Schemas, Instances and Database State
cf database
Database Schema (meta-data): The description of a database. Includes
descriptions of the database structure and the constraints that should hold
on the database.
Schema Diagram: A diagrammatic display of (some aspects of ) a
database schema. (refer to Fig 2.1 2-5)
Database Instance: The actual data stored in a database at a particular
moment in time. Also called database state ( or occurrence, snapshot)
(refer to Fig 1.2 2-6)
Each schema construct has its own current set of instances.
The database schema changes very infrequently. The database state
changes every time the database is updated. Schema is also called
intension, whereas state is called extension.
2-3 5
6. Figure 2.1 Schema diagram for UNIVERSITY database
schema construct
Known data:
name of record types, data items
2-4a 6
8. define
empty state
load
initial state
update
valid state
state satisfy database schema
update
2-3 8
9. 2.2 DBMS Architecture and Data Independence
2.2.1 Three-Schema Architecture
Proposed to support DBMS characteristics of:
- Insulation of programs and data/program and operations
(program-data and program-operation independence)
- Support of multiple views of the data.
- Use of catalog (database description)
Defines DBMS schema at three levels: (see 2-9)
- Internal schema at the internal level to describe data storage structures and access
paths. Typically uses a physical data model.
- Conceptual schema at the conceptual level to describe the structure and constraints
for the whole database. Uses a conceptual or an implementation data model.
- External schema at the external level to describe the various user views. Usually
uses the same data model as the conceptual level or high-level data model.
Mappings among schema levels are also needed. Programs refer to an external
schema, 2-5 9
10. Figure 2.2 The Three-schema architecture 2-6
2-6 10
11. 2.2.2 Data Independence By adding or removing a record type or data
item to
· expand the database (2-11)
· reduce the database
Logical Data Independence: The capacity to change the conceptual schema without
having to change the external schemas and their application programs.
Physical Data Independence: The capacity to change the internal schema without
having to change the conceptual schema.
Reorganize physical files to improve performance
e.g. List all sections offered in Fall 1998
When a schema at a lower level is changed, only the mappings between this
schema and higher-lever schemas need to be changed in a DBMS that fully supports
data independence. The higher-level schemas themselves are unchanged. Hence, the
application programs need not be changed since they refer to the external schemas.
Disadvantages of two levels of mappings:
Overhead during compilation or execution of a query or program
2-7 11
13. 2.3 Database Languages and Interfaces
provide appropriate languages and interfaces for each category of users.
2.3.1 DBMS Languages
Data Definition Language (DDL): Used by the DBA and database designers to
specify the conceptual schema of a database. In many DBMSs, the DDL is also
used to define internal and external schemas (views). In some DBMSs, separate
storage definition language (SDL) and view definition language (VDL) are
used to define internal and external schemas.
DDL Compiler
Data Manipulation Language (DML): Used to specify database retrievals and
updates (insertion, deletion, modifications)
- DML commands (data sublanguage) can be embedded in a general-purpose
programming language (host language).
- Alternatively, stand-alone DML commands can be applied directly (query
language).
2-8 13
14. Types of DML
-Procedural DML:
• Also called record-at-a-time (record-oriented) or low-level DML
• Must be embedded in a programming language.
• Searches for and retrieves individual database records and uses looping
and other constructs of the host programming language to retrieve multiple
records.
-Declarative or non-procedural DML:
• Also called set-at-a-time (set-oriented) or high-level DML.
• Can be used as a stand-alone query language or can be embedded in a
programming language.
• Searches for and retrieves information from multiple related database
records in a single command.
- host language: general-purpose language
- data sublanguage: DML
- C++
2-9 14
15. 2.3.2 DBMS Interfaces
- Stand-alone query language interfaces. (casual end user)
- Programmer interfaces for embedding DML in programming
languages: (programmer)
-Pre-compiler Approach
-Procedure (Subroutine) Call Approach
- User-friendly interfaces:
-Menu-based Interfaces for Browsing.
-Forms-based Interfaces.
-Graphical User Interfaces.
-Natural language Interfaces
-Combination of the above
-Interfaces for Parametic Users (using function keys)
- Interfaces for the DBA:
-Creating accounts, granting authorizations
-Setting system parameters
-Changing schemas or access path
2-10 15
16. 2.4 The Database System Environment
2.4.1 DBMS Component Modules
Figure 2.3
2-11 16
17. 2.4.2 Database System Utilities
To perform certain functions such as:
- Loading data stored in files into a database. Conversion tool
- Backing up the database periodically on storage.
- File reorganizing database file structures.
- Report generation utilities.
- Performance monitoring utilities.
- Other functions, such as sorting, user monitoring,
data compression, etc.
2-12 17
18. 2.4.3 Tools, Application Environments, and
Communications Facilities
Data dictionary utility:
- Used to store schema descriptions and other information such as design
decisions, application program descriptions, user information, usage
standards, etc. (comment)
-Active data dictionary is accessed by DBMS software and users/DBA.
-Passive data dictionary is accessed by users/DBA only.
Communications Facilities
- Allow users at locations remote from the database system site to access
the database.
DB (DBMS)/DC (Data Communication System)
2-12 18
19. 2.5 Classification of Database Management Systems
Based on the data model used:
•Data models
-Traditional: Relational, Network (see 2-19), Hierarchical
- Emerging: Object-oriented, Semantic, Entity- Relationship, other.
Other classifications:
•Number of users : Single-user (typically used with personal computers) vs.
multi-user (most DBMSs)
•Number of sites:
Centralized (uses a single computer) vs. distributed (uses multiple computers).
Homogeneous vs. Heterogeneous
•Types of access paths used. (inverted file structures, …)
•Purpose general purpose
special purpose
e.g. airline reservations, telephone directory, on-line transaction
processing system
2-13 19