TD MXC Oracle Session Clarke

8/14/2019 TD MXC Oracle Session Clarke

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EclipseLink JPA

in GlassFish

Doug Clarke

Director of Product Management

Oracle


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Eclipse Persistence Services

EclipseLink

Eclipse Persistence Services Project

(EclipseLink)

DBWSDBWS

SDOSDO

EISEIS

MOXyMOXy

JPAJPA

XML Data Legacy SystemsDatabases

Java SEJava SE Java EEJava EE OSGiOSGi SpringSpring ADFADF


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History of EclipseLink

1996 2008

TopLinkEssentials


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Significance of EclipseLink

First comprehensive open source persistence solution

Object-Relational and much more

Based upon product with 12 years of commercial

usage

Shared infrastructure Easily share the same domain model with multiple

persistence technologies

Leverage metadata for multiple services

Important part of the GlassFish and EclipseEcosystems


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EclipseLink JPA

JPA 1.0 compliant implementation

Java EE, Java SE, Web, Spring, and OSGi

Any JDBC/SQL compliant database

Advanced database extensions: stored procedures, native SQL,

Key infrastructure: Caching, Locking, Query Framework, Mapping,

JDBC connection pooling

Diagnostics: Logging, Profiling

DDL Generation

Customization callbacks

Highly Extensible

plus many valuable advanced features


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Caching

Hold objects in-memory to avoid unnecessary

database trips and object construction

Cache manages identity to support bidirectional and

cyclical relationships

Flexible caching options ensure that you get

maximum performance

Numerous locking, refreshing, and synchronization

options are available to minimize cache staleness

Queries can be run in-memory only against the cache

Cache Coordination supports clustering


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Cache Configuration

Cache Shared (L2)/Isolated (L1 only) Entity cachenot data cache

Cache Type & Size Soft/Hard Weak

Weak

Full

None

@Cache(type = CacheType.HARD_WEAK,size = 500,

isolated = true,coordinationType =

INVALIDATE_CHANGED_OBJECTS)


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EclipseLink JPA Caching

EntityManager EntityManagerFactory

L2 Cache

(Shared )

L1 Cache

Cache Coordination


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Minimize stale cache

Configure the cache relative to application datas

usage Is the data shared between users/processes?

Is the data volatile?

Only through JPA application?

Through direct DB modification?

Ensure you protect any data that can be concurrently

modified with a locking strategy

Must handle optimistic lock failures on flush/commit

Use query refreshing to minimize optimistic lock

failures


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Leveraging the Shared Cache: Reading

Client-2Client-1

EntityManager-1

EntityManagerFactory

L2 Cache Connection PoolConnection

ConnectionConnection

Connection

EntityManager-2

L1 CacheL1 Cache

Connection

1

2

3

5

6

7

84


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EntityManager-2

L1 Cache


Connection PoolConnection



Leveraging the Shared Cache: Writing

Client-2

L2 Cache

1

2

3

4


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Connection PoolConnection



Leveraging the Shared Cache: Writing

L2 Cache


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Advanced Mappings

@Converter

@BasicMap and @BasicCollection

Mapping to database structures @StructConverter Structs, ADTs

XML types, PL/SQL Records

Mapping features Private Owned

Join/Batch Fetch

Returning


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@Entity

public class Employee {

@Idprivate int id;

private String name;

@OneToMany(mappedBy=owner)private List phones;

private Money salary

}

@Cache(type=SOFT_WEAK, coordinationType=SEND_OBJECT_CHANGES)

@Converter(name=money, converterClass=MoneyConverter.class)@OptimisticLocking(type=CHANGED_COLUMNS)

Advanced Mapping Example

@Convert(money)


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Advanced Querying

Support for supplying customizing queries

Native SQL

@NamedStoredProcQuery

Graph Loading Optimizations Join and Batch Fetch multi-level

Cache Usage: In-memory

Result caching


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Transactions

Java apps typically support many clients sharing

small number of db connections

Ideally would like to minimize length of transaction on

database

Time

Begin Txn

Commit Txn Begin TxnCommit Txn


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Transaction Features

Minimizes database interactions

Only the minimal updates are sent to the database

Respect database integrity Orders INSERT, UPDATE and DELETE statements

JTA and RESOURCE_LOCAL support

Attribute-level change tracking

EntityManager flush SQL prior to commit

Bulk Update and Delete Cached entities effected


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Concurrency Protection - Locking

Optimistic concurrency included in JPA 1.0, but no

support for pessimistic locking is specified

EclipseLink has advanced optimistic locking

strategies Numeric, Timestamp, All fields, Selected fields, Changed field

EntityManager lock() method can be used with

optimistic locking, and error handling

EclipseLink supports pessimistic locking through

query hints

query.setHint(PESSIMISTIC_LOCK, LockNoWait);


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Weaving

EclipseLink makes use of Weaving (ASM) to

introduce additional functionality into the JPA entity

classes Needed for M:1 and 1:1 lazy fetching

Integrated with Java EE compliant App Servers and Spring2.0

Available for Java SE using JDK/JREs javaagent:

Optional

Static weaving also supported

Weaving of .class files before deployment


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JPA Configuration Options

Annotations

JPA

EclipseLink

ORM.XML JPA

EclipseLink

JPA + EclipseLink

Defaults Configuration by Exception


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Database Platform

XML:


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Target Database Platform

TargetDatabase (org.eclipse.persistence.jpa.config)

Auto (Default)

Oracle, Oracle8i, Oracle9i, Oracle10g, Oracle11, TimesTen

DB2, DB2Mainframe

Derby, JavaDB, MySQL

Informix

HSQL, PointBase

PostgreSQL

SQLAnyWhere SQLServer, DBase

Sybase


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Server Platform

Enables simplified configuration of the target

application server

Used to enable integration with: JTA transaction manager

Logging

JDBC connection un-wrapping


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Target Server Options

TargetServer (org.eclipse.persistence.jpa.config)

None (Default)

OC4J, OC4J_10_1_3, OC4J_11_1_1

SunAS9

WebSphere WebSphere_6_1

WebLogic, WebLogic_9, WebLogic_10

JBoss


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JDBC Connection Settings

...


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Logging

...


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DDL Generation

Standard enables it but does not currently dictate that

providers support it

Mapping metadata specifies how DDL should be

generated

Vendors may offer differing levels of support,

including: Generating DDL to a file only

Generating and executing DDL in DB

Dropping existing tables before creating new ones


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DDL Generation

...


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Customization Using Properties

...

...


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Descriptor & Session Customizers

public class MySessionCustomizerimplements SessionCustomizer {

public void customize(Session session) {session.setProfiler(new PerformanceProfiler());

}}

public class MyDescriptorCustomizerimplements DescriptorCustomizer {

public void customize(ClassDescriptor desc) {desc.disableCacheHits();}

}


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Performance and Tuning

Highly configurable and tunable Guiding principle minimize and optimize database

interactions

No two applications are the same, EclipseLink allows fordecisions on what specific behavior needs to be configurable

depending on situation Flexibility of EclipseLink allows efficient business

models and relational schemas to be used

Leverages underlying performance tuning features

Java, JDBC and the underlying database technology Batch Writing

Parameter Binding

Statement Caching


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Performance and Tuning

Minimal Writes, Updates

Batch Reading, Writing

SQL ordering

Transformation support

Existence checks Stored procedures

Statement Caching

Scrolling cursors

Projection Queries

Partial Attribute Queries

Just in Time reading

Automatic change detection

Caching policies and sizes

Parameterized SQL (binding)

Pre-allocation of sequencenumbers

Cache Coordination

Optimistic, Pessimistic locking

Joining object retrieval

optimizationIn memory querying

Dynamic queries

AND MUCH MORE!


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EclipseLink Status

Incubating Technology Project Initial contribution of Oracle TopLink complete

Full documentation available on Wiki

Producing Monthly Milestone builds

Milestones included in GlassFish V3 Milestones

1.0 release planned for July 2008 JPA 1.0, SDO 2.1, JAXB

Simplified XML and annotation config of advanced features

Packaged for Java SE/EE and OSGi bundles

Beyond 1.0

JPA 2.0 (Reference Implementation) Database Web Services

Data Access Service (DAS) 1.0

and much more


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Getting Started with EclipseLink JPA

EclipseLink Project

http://www.eclipse.org/eclipselink

Eclipse newsgroup: eclipse.technology.eclipselink

GlassFish V3

https://glassfish.dev.java.net/

Open Source JPA Tools NetBeanshttp://www.netbeans.org

Dali JPA Toolshttp://www.eclipse.org/dali


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TD MXC Oracle Session Clarke

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