Architecture and Interface of Scalable Distributed Database System SD-SQL Server

Architecture and Interface of

Scalable Distributed Database System

SD-SQL Server

Soror SAHRI Witold LITWIN Thomas SCHWARTZ

[email protected] [email protected] [email protected]

Ceria Laboratory Comp. Eng. Dep. Paris-Dauphine University Santa

Clara U.

The IASTED International Conference onDBA 2006

IASTED-DBA 2006, Innsbruck, Feb 15th, 2006

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Outline

IntroductionOverall ArchitectureApplication InterfaceImplementationConclusion


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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.

A Scalable Distributed Database System:

SD-DBS

Solution?

Introduction


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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

Introduction


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SD-SQL Server Architecture

Split

User/ApplicationUser/Application

LinkedSQL

Servers

D1NDBs D2 Di Di+1

_D1_T

SD-SQLserver

SD-SQLserver

SD-SQLclient

D1_T

SD-SQL Server

Managers

_D1_T_D1_T

T

sd_select

SD-SQLpeer

sd_insert


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DB1 SDB

SD-SQL Server ArchitectureNodes, SDBs, NDBs

Node1 Node2 Node3 Node i

DB1

……

DB1 DB1

DB2 SDB

DB2 DB2

MDB


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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

SD-SQL Server ArchitectureScalable Tables: Segments


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SD-SQL Server ArchitectureScalable 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


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SD-SQL Server ArchitectureImages

Images hide the scalable table segments An image is a distributed updateable partitioned

view of a scalable tableUnion-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


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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

SD-SQL Server ArchitectureImages

…


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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


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Use of the SkyServer DB as benchmark

http://research.microsoft.com/~gray/SDSS PhotoObj table as a scalable table. PhotoObj has 158,426 tuples (about 260 MB)

Use of the laboratory machines Ceria, Dell1, Dell2….


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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’


Nodes Management


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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’


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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’


Scalable Tables


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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’


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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


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SD-SQL Application Interface


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SD-SQL Application InterfaceCommand 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 2005-12-13, 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.


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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

Thank you.

For more details:

http://ceria.dauphine.fr

Architecture and Interface of Scalable Distributed Database System SD-SQL Server

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