distributed dbms - cs712 power point slides lecture 11
TRANSCRIPT
![Page 1: Distributed DBMS - CS712 Power Point Slides Lecture 11](https://reader035.vdocument.in/reader035/viewer/2022073017/544a5be1b1af9fc2588b4812/html5/thumbnails/1.jpg)
Distributed Database Distributed Database Management System Management System Distributed Database Distributed Database Management System Management System
Lecture 10Lecture 10
![Page 2: Distributed DBMS - CS712 Power Point Slides Lecture 11](https://reader035.vdocument.in/reader035/viewer/2022073017/544a5be1b1af9fc2588b4812/html5/thumbnails/2.jpg)
Virtual University of Pakistan
2
Major DDBS ArchitecturesMajor DDBS ArchitecturesMajor DDBS ArchitecturesMajor DDBS Architectures
![Page 3: Distributed DBMS - CS712 Power Point Slides Lecture 11](https://reader035.vdocument.in/reader035/viewer/2022073017/544a5be1b1af9fc2588b4812/html5/thumbnails/3.jpg)
Virtual University of Pakistan
3
Client-Server ArchitectureClient-Server ArchitectureClient-Server ArchitectureClient-Server Architecture
• Basic idea is to distribute Basic idea is to distribute functionalityfunctionality
• Gives two level architectureGives two level architecture• The term used in different The term used in different
meanings; generally C and S refer meanings; generally C and S refer to processes, may be running at to processes, may be running at the same machinesthe same machines
![Page 4: Distributed DBMS - CS712 Power Point Slides Lecture 11](https://reader035.vdocument.in/reader035/viewer/2022073017/544a5be1b1af9fc2588b4812/html5/thumbnails/4.jpg)
Virtual University of Pakistan
4
–As you can see in the figureAs you can see in the figure–Server performs most of the data Server performs most of the data
Management;Management;• Query Processing
• Transaction and Storage Management
–Client, mainly has Client, mainly has • application and user interface • a client module of DBMS• Data and lock management cached their
sometimes
–OS and Communication s/w OS and Communication s/w running at bothrunning at both
![Page 5: Distributed DBMS - CS712 Power Point Slides Lecture 11](https://reader035.vdocument.in/reader035/viewer/2022073017/544a5be1b1af9fc2588b4812/html5/thumbnails/5.jpg)
Virtual University of Pakistan
5
• Client passes user queries to Client passes user queries to server without trying to server without trying to understand or optimize them understand or optimize them
• One Server Multiple ClientsOne Server Multiple Clients• Multiple ServersMultiple Servers
–One Server at a timeOne Server at a time–Multiple Servers (transparently) at a Multiple Servers (transparently) at a
timetime
![Page 6: Distributed DBMS - CS712 Power Point Slides Lecture 11](https://reader035.vdocument.in/reader035/viewer/2022073017/544a5be1b1af9fc2588b4812/html5/thumbnails/6.jpg)
Virtual University of Pakistan
6
Peer-to-Peer Distributed SystemsPeer-to-Peer Distributed SystemsPeer-to-Peer Distributed SystemsPeer-to-Peer Distributed Systems
![Page 7: Distributed DBMS - CS712 Power Point Slides Lecture 11](https://reader035.vdocument.in/reader035/viewer/2022073017/544a5be1b1af9fc2588b4812/html5/thumbnails/7.jpg)
Virtual University of Pakistan
7
LIS1 LIS2 LISn
LCS1 LCS2 LCSn
ES1 ES2 ESn
GCS
ES1
![Page 8: Distributed DBMS - CS712 Power Point Slides Lecture 11](https://reader035.vdocument.in/reader035/viewer/2022073017/544a5be1b1af9fc2588b4812/html5/thumbnails/8.jpg)
Virtual University of Pakistan
8
• Physical data organization at Physical data organization at each site defining Local Internal each site defining Local Internal SchemasSchemas
• On top of that, Local Conceptual On top of that, Local Conceptual SchemaSchema
• Then the overall view is depicted Then the overall view is depicted by Global conceptual schema that by Global conceptual schema that supports the External schemas supports the External schemas
![Page 9: Distributed DBMS - CS712 Power Point Slides Lecture 11](https://reader035.vdocument.in/reader035/viewer/2022073017/544a5be1b1af9fc2588b4812/html5/thumbnails/9.jpg)
Virtual University of Pakistan
9
• Transparencies Supported Transparencies Supported
• Extension of ANSI/SPARC ModelExtension of ANSI/SPARC Model
• Data Independence supportedData Independence supported
• Local Data Dictionary and global Local Data Dictionary and global existexist
• Both support local and global Both support local and global mappingsmappings
![Page 10: Distributed DBMS - CS712 Power Point Slides Lecture 11](https://reader035.vdocument.in/reader035/viewer/2022073017/544a5be1b1af9fc2588b4812/html5/thumbnails/10.jpg)
Virtual University of Pakistan
10
Interpreting user commands
and formats results
Checks if user query can be processed
Optimized execution strategy
Global queries to local ones
Coordinates distribution execution of user requests
![Page 11: Distributed DBMS - CS712 Power Point Slides Lecture 11](https://reader035.vdocument.in/reader035/viewer/2022073017/544a5be1b1af9fc2588b4812/html5/thumbnails/11.jpg)
Virtual University of Pakistan
11
Chooses best access path to any data item
Makes sure the consistency of local data even in case of failure
Physically accesses the data as per the commands generated by query optimizer. Interacts with the OS
![Page 12: Distributed DBMS - CS712 Power Point Slides Lecture 11](https://reader035.vdocument.in/reader035/viewer/2022073017/544a5be1b1af9fc2588b4812/html5/thumbnails/12.jpg)
Virtual University of Pakistan
12
A Multidatabase SystemA Multidatabase System• Provides access from multiple, Provides access from multiple,
autonomous heterogeneous, and autonomous heterogeneous, and distributed databases. Two Major distributed databases. Two Major architectures:architectures:
• Global Schema Architecture• Federated Schema Architecture
Major DDBS Architectures-IIIMajor DDBS Architectures-IIIMajor DDBS Architectures-IIIMajor DDBS Architectures-III
![Page 13: Distributed DBMS - CS712 Power Point Slides Lecture 11](https://reader035.vdocument.in/reader035/viewer/2022073017/544a5be1b1af9fc2588b4812/html5/thumbnails/13.jpg)
Virtual University of Pakistan
13
Global Schema Architecture
L ExternalSchema
G ExternalSchema
GlobalSchema
ComponentSchema
ComponentSchema• • •
LocalSchema
LocalSchema• • •
Schema Translation
Schema Integration
G ExternalSchema
L ExternalSchema