1. Architecture and Interface of Scalable Distributed Database System SD-SQL Server
Soror SAHRI Witold LITWIN Thomas SCHWARTZ
Ceria Laboratory Comp. Eng. Dep Paris-Dauphine University Santa Clara U.
The IASTED International Conference on DBA 2006
IASTED - DBA 2006, Innsbruck, February 14-16, 2006

2. IASTED-DBA 2006, Innsbruck, Feb 15th, 2006
Outline
Introduction
Overall Architecture
Application Interface
Implementation
Conclusion
IASTED-DBA 2006, Innsbruck, Feb 15th, 2006
IASTED - DBA 2006, Innsbruck, February 14-16, 2006

3. Introduction Most of DBSs have distributed/parallel versions
SQL Server, Oracle, DB2
DBSs do not provide dynamically scalable tables.
All require manual repartitioning when tables scale-up.
Solution?
A Scalable Distributed Database System:
SD-DBS
IASTED-DBA 2006, Innsbruck, Feb 15th, 2006

4. IASTED-DBA 2006, Innsbruck, Feb 15th, 2006
Introduction
Applies SDDS technology to DBSs
Why SDDSs?
Provide many scalable distributed partitioning schemes.
LH*, RP*, k-RP*, LH*RS…
These schemes can serve as the basis for SD-DBS architecture
IASTED-DBA 2006, Innsbruck, Feb 15th, 2006

5. SD-SQL Server Architecture
User/Application
User/Application
sd_select
sd_insert
SD-SQL Server Managers
SD-SQL client
SD-SQL server
SD-SQL server
SD-SQL peer
Linked SQL Servers
D1_T T
_D1_T
_D1_T
Split
_D1_T
NDBs D1 D2 Di
Di+1
IASTED-DBA 2006, Innsbruck, Feb 15th, 2006

6. SD-SQL Server Architecture Nodes, SDBs, NDBs
MDB
Node1
Node2
Node3
Node i ……
DB1
DB2
DB1
DB2
DB1
DB2 SDB
DB1 SDB
IASTED-DBA 2006, Innsbruck, Feb 15th, 2006

7. A scalable (distributed) table is a collection of segments
SD-SQL Server Architecture Scalable Tables: Segments
A scalable (distributed) table is a collection of segments
Segments are SQL tables
A scalable table has, initially, only one primary segment
At some server or peer NDB
The number of segments in a scalable table is variable.
If a segment overflows, its split is triggered
IASTED-DBA 2006, Innsbruck, Feb 15th, 2006
IASTED - DBA 2006, Innsbruck, February 14-16, 2006

8. SD-SQL Server Architecture Scalable Tables: Split
A split occurs when an insert overflows the segment capacity
Splits produce other segments for a scalable table.
Each is located at a different NDB
Within the SDB
If there is not enough NDBs, splits dynamically append new ones
IASTED-DBA 2006, Innsbruck, Feb 15th, 2006

9. SD-SQL Server Architecture Images
Images hide the scalable table segments
An image is a distributed updateable partitioned view of a scalable table
Union-all view with check constraints
An image presents the scalable table partitioning
It do not address any new segments resulted from a split
Each scalable table has only one primary image and one or several secondary images
IASTED-DBA 2006, Innsbruck, Feb 15th, 2006

10. … SD-SQL Server Architecture Images T Scalable Table Primary Image
DB1 SDB
N1.DB1
N2.DB1
Ni.DB1
T Scalable Table …
Primary Image
CREATE VIEW T AS SELECT * FROM N1.DB1._N3_T
UNION ALL SELECT * FROM N2.DB1._N3_T
UNION ALL SELECT * FROM Ni.DB1._N3_T
IASTED-DBA 2006, Innsbruck, Feb 15th, 2006

11. SD-SQL Server Application Interface
The application interface manipulates scalable tables through SD-SQL Server commands.
The SD-SQL Server commands start with ‘sd_’ to distinguish from SQL Server commands for static tables.
INSERT sd_insert
CREATE TABLE sd_create_table
IASTED-DBA 2006, Innsbruck, Feb 15th, 2006
IASTED - DBA 2006, Innsbruck, February 14-16, 2006

12. SD-SQL Server Application Interface
Use of the SkyServer DB as benchmark
PhotoObj table as a scalable table.
PhotoObj has 158,426 tuples (about 260 MB)
Use of the laboratory machines
Ceria, Dell1, Dell2….
IASTED-DBA 2006, Innsbruck, Feb 15th, 2006

13. SD-SQL Server Application Interface Nodes Management
Node Creation
sd_create_node ‘Dell1’ /* Server by default */
sd_create_node ‘Ceria’, ‘client’
Node Alteration
sd_alter_node ‘Ceria’, ‘ADD server’ /* Becomes peer*/
Node Removal
sd_drop_node ‘Ceria’
IASTED-DBA 2006, Innsbruck, Feb 15th, 2006
IASTED - DBA 2006, Innsbruck, February 14-16, 2006

14. SD-SQL Server Application Interface SDB/NDB Management
SDB Creation
sd_create_scalable_database
‘SkyServer’, ‘Dell1’, ‘Server’, 2
/* Creates the primary SkyServer NDB as well at Dell1*/
SDB Alteration
sd_create_node_database ‘SkyServer’, ‘Ceria’, ‘Client’
SDB Removal
sd_drop_scalable_database ‘SkyServer’
IASTED-DBA 2006, Innsbruck, Feb 15th, 2006

15. SD-SQL Server Application Interface Scalable Tables
Scalable Table Creation
sd_create_table ‘PhotoObj (objid BIGINT PRIMARY KEY…)’, 10000
Scalable Table Alteration
sd_alter_table ‘PhotoObj ADD t INT’, 1000
sd_create_index ‘run_index ON Photoobj (run)’
sd_drop_index ‘PhotoObj.run_index’
Scalable Table Removal
sd_drop_table ‘PhotoObj’
IASTED-DBA 2006, Innsbruck, Feb 15th, 2006

16. SD-SQL Server Application Interface Images
Secondary Image Creation
sd_create_image ‘Ceria’, ‘PhotoObj’
sd_create_image ‘Ceria2’, ‘PhotoObj’
Secondary Image Removal
sd_drop_image 'PhotoObj’
IASTED-DBA 2006, Innsbruck, Feb 15th, 2006

17. SD-SQL Server Application Interface Scalable Queries
USE Skyserver /* SQL Server command */
Scalable Update Queries
sd_insert ‘INTO PhotoObj SELECT * FROM Ceria5.Skyserver-S.PhotoObj’
Scalable Search Queries
sd_select ‘* FROM PhotoObj’
sd_select ‘TOP 5000 * INTO PhotoObj1 FROM PhotoObj’, 500
IASTED-DBA 2006, Innsbruck, Feb 15th, 2006
IASTED - DBA 2006, Innsbruck, February 14-16, 2006

18. SD-SQL Application Interface
IASTED-DBA 2006, Innsbruck, Feb 15th, 2006

19. SD-SQL Application Interface Command Processing
SD-SQL Server uses distributed stored procedures with dynamic SQL…
SD-SQL Server processes every command as a distributed transaction at Repeatable Read isolation level
See details in the papers
“SD-SQL Server: a Scalable Distributed Database System”, CERIA Research Report , December 2005 
“Overview of Scalable Distributed Database System SD-SQL Server”, Intl. Workshop on Distributed Data and Structures, WDAS 2006, Santa Clara, CA, Carleton Scientific.
IASTED-DBA 2006, Innsbruck, Feb 15th, 2006

20. IASTED-DBA 2006, Innsbruck, Feb 15th, 2006
Conclusion
Scalable distributed databases with scalable tables are now a reality with SD-SQL Server
No more manual repartitioning
Unlike in any other DBS we know about
See the “Related Work” in the paper
The performance analysis proves
Efficiency of our design
Immediate utility of SD-SQL Server
IASTED-DBA 2006, Innsbruck, Feb 15th, 2006

21. For more details:
Thank you.