Ogh20071212 b.van Halderen m. Schapendonk en m. v.d. Plas

8/22/2019 Ogh20071212 b.van Halderen m. Schapendonk en m. v.d. Plas

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Oracle in Open Source projects

Oracle in

Open Source ProjectsBerry van Halderen [email protected]


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Oracle in Open Source

Outline

About Hippo

Architecture Hippo software and open source

The storage problem for (open source) software packages

Interoperability and standards

JCR and JPA/JDO

How this ties into Hippo and Oracle


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About Hippo

Hippo develops and provides services for its

Content Management System (CMS)

Develop Open Source software;

Participate in open standards;

Web and Java-based content software;

Hippo works directly for customers, but wants to focus as softwarecompany.


4/26Oracle in Open Source

Just a glance...



The advantages of being open

Customers have ensure maintainability

Base software developed by more than one company

Can provide confidence of correctness and checks

Allows customer or third party extensions

More modularized applications

Better interoperability

No free lunch, still requires support and customization



Architecture

Central repository delivering common functionalities

Applications are CMS, websites, ...



Architecture

All applications, even CMS are just web applications

Central repository delivering common functions

Get, retrieve, search documents

Versioning

Workflow

Hierarchical storage

Typed and unstructured data

Locking

Repository itself persists into files, databases, etcetera

All communication and storage should be performed using thecentral repository



Why a repository?

Extended, application domain specific functionality, needed.

SQL 'standard' to diverse and generic for single software baseto work.

Repository uses simple database model andfilesystem to store data.

Because all applications use repository as storage,back-end specific storage is hidden.

However repository still has to deal with back-enddifferences.



Advent of abstraction layers that are application specific

jdbc/repositoryDataSourceorg.apache.slide.store.impl.rdbms.OracleRDBMSAdapterSLIDE_SLIDE_false

Usage of adapter layer in software;

Internal, application specific, abstraction on storagesystem used.

However each software module will have its ownadapter


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How does Hippo use Oracle

No oracle specific development because applicationbase must be generic;

Just like any other database and application server

Product should run within any application container andusing any back-end storage.

Small compartimized component provide

connection to back-end store.

http://flickr.com/photos/92011777@N00/228570232/


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It was just too simple

Two problems, first:

Open source projects are technical subprojects, notend-applications.

Multiple projects are put together in one application. Each project potentially its own storage adapter.

Second: we're not alone


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Other repositories out there

We want inter-operability


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Standarization

How independently developed software can co-operate;

Standardize

Best effort standardization:

Application domain, rather than full generic; Mostly on API, quering just as basis;

Open source requires open standards to be involved.


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Standarization approaches

I.Application interoperability

II.Storage abstraction layers that capture applicationdomain knowledge

I. Java Content Repository: JCR

II.Java Persistency:

Plain Java objects mapped to database storage.

Java Standards (JSRs):


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Java Content Repository (JCR)

JSR-170, JSR-283 in preparation

Standardized API for Content repositories

This is not a generic database access

But a Java API for accessing content in webapplication domain for CMS, DMS, etcetera.

http://flickr.com/photos/openthreads/234957983/


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JCR provides

Versioning

Hierarchical storage

Locking

Observation Hierarchical type management, but also

unstructured content

But no workflow,

and leaves query languages partly open.


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Example

Import javax.jcr.*;

Session session = repository.login();Node node = session.getRootNode().getNode(documents).getNode(artists/queen);

Node album = node.addNode(A day at the races, nodetype:album);album.setProperty(year, 1976);album.setProperty(genre, new String[] { pop rock, progressive rock });

Node song = album.addNode(Teo Torriate, nodetype:song);song.setProperty(length, 357);

session.save();session.commit();

queryManager.createQuery(SELECT * FROM nodetype:song WHERE length > 300, Query.SQL)queryManager.createQuery(/documents/artists//[@length > 300], Query.XPATH);Query query = queryManager.getQuery(session.getRootNode().getNode(/queries/stored);

QueryResult result = query.execute();for(NodeIterator iter = result.getNodes(); iter.hasNext(); ) {

node = iter.nextNode();}


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Object Relational/Content Mapping (ORM/OCM)

Plain Java object programmingpreferred by developers

Not the intricates of having tofetch and store data, fetchgroups

OCM provides layer that mapsJava objects to a databaseschema.

Once initial Java object isobtained, all referenced objectsare also available.

Fetch groups allow application-

Java class Database

Mapping description

Database connectordescription


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Object Mapping Standards

Alternative standards: JPA and JDO (plus Hibernate, etc.)

Differences in expressiveness, but all use same approach:

Mapping description file, or

Annotations Plus back-end storage descriptor

Mapping allow application domain knowledge

and seperation between storage method and code.


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JDO / JPA Annotations

@Entitypublic class Employee implements Serializable {

private int employeeId;

@Idpublic int getEmployeeId() { return employeeId; }

@JoinColumn(name="MANAGER_ID", referencedColumnName="EMP_ID")public Collection getManagedEmployees();

}

@NamedQuery(name="findAllEmployees",query="SELECT * FROM EMPLOYEE WHERE MGR=1"hints={ @QueryHint={name=TopLinkQueryHints.BIND_PARAMETERS} }

)

Annotations in Java5 describing how to map to schema:

Specialized queries can be used too, if really needed:


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JDO / JPA Mapping description

Alternative to use mapping description

Here, also targetted queries are possible.


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OCM and JCR do not conflict

OCM and JCR do not conflict:

OCM on top of JCR

http://flickr.com/photos/17271969@N00/16402704/

Browse, versioning, etc by JCR.Programming paradigm by OCM


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Oracle and open source / open standards

One view is that for Oracle open source is just anotherapplication

this is rightfully so..

Oracle wants to be the information provider to all applications

Open standards promote this, and allow open source providesto integrate with Oracle products.


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Oracle involvement in Open Standards

Is Oracle involved in Open Standards?

JSR-4

JSR-21JSR-15

JSR-10

JSR-24

JSR-30

JSR-37JSR-40

JSR-43

JSR-45 JSR-48

JSR-51

JSR-56

JSR-69

JSR-72JSR-74

JSR-76

JSR-94JSR-99

JSR-106

JSR-107

JSR-115

JSR-121

JSR-123

JSR-126

JSR-128

JSR-131

JSR-133 JSR-138

JSR-139

JSR-142

JSR-144

JSR-147JSR-155

JSR-156

JSR-160

JSR-163

JSR-164

JSR-165

JSR-167

JSR-169

JSR-171

JSR-174

JSR-175

JSR-176

JSR-181

JSR-182

JSR-186

JSR-187

JSR-188

JSR-198

JSR-199

JSR-72

JSR-200

JSR-201

JSR-202

JSR-203

JSR-204

JSR-207

JSR-208

JSR-212

JSR-215

JSR-223

JSR-227

JSR-233

JSR-241

JSR-250

JSR-251

JSR-254

JSR-262

JSR-264

JSR-265

JSR-269

JSR-270

JSR-276

JSR-277

JSR-284

JSR-289

JSR-291 JSR-292

JSR-294

JSR-295

JSR-303

JSR-305

JSR-306

JSR-309

JSR-310

JSR-316

JSR-322JSR-318JSR-317

JSR-315

JSR-314

JSR-313

JSR-301

JSR-299

JSR-296

JSR-286 Portlet 2.0JSR-255

JSR-262

JSR-252 JavaServer Faces 2.0

JSR-247

JSR-245 JSP 2.1

JSR-244

JSR-243 JDO 2.0

JSR-225

JSR-224

JSR-222

JSR-221

JSR-220

JSR-206

JSR-196

JSR-173

JSR-172

JSR-170 JCR

JSR-168

JSR-154JSR-153

JSR-152

JSR151

JSR-127

JSR-117

JSR-114

JSR-112JSR-110

JSR-109

JSR-101

JSR-88

JSR-73JSR-67

JSR-53

JSR-52

JSR-31JSR-26

JSR-12 JDO

JSR-16

JSR-19 JavaBeans

JSR-5


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Oracle does JCR

Oracle involved in JCR (JSR-170, 283)

Oracle involved in JPA/JDO (JSR-243, 220, ..)

Implementations for JCR, JDO/JPA (TopLink)

Standards allow for interoperability

e.g. Use specialized Hippo JCR together with Oracle JCR tools

Or Oracle JCR combined with Hippo JCR;

Application programmers can use same interface, and just point to different

implementation when addressing specific needs.


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Wrapping up

Open source and open standards target less vendorcentric development and better interoperability;

Attention in open source world to use openstandards

Application domain solutions

rather than end-application specific or too generic;

use localized queries that can be tailored to back-end.

Open source developers and

other vendors co-operating in

open standards.

http://flickr.com/photos/thepartycow/296816170/

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Ogh20071212 b.van Halderen m. Schapendonk en m. v.d. Plas