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![Hibernate Envers • Provides historical versioning and auditing (“SCM for data”) • Each transaction == a “revision” • Revision #s are global --> querying for a historical snapshot of the entire database is possible • Requires – @Audited on the entity or individual properties – [entity]_AUD tables to store the historical data (DDL created automated if using hbm2ddl, otherwise it’s exportable) • Duplicate data? Yes. • Powerful queries/capabilities > cheap mem • Highly configurable](https://image.slidesharecdn.com/hibernateormfeatures-140223193044-phpapp02/75/Not-Just-ORM-Powerful-Hibernate-ORM-Features-and-Capabilities-21-2048.jpg)
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Not Just ORM: Powerful Hibernate ORM Features and Capabilities
The document presents advanced features and capabilities of Hibernate ORM, elucidating its support for object-relational mapping, multi-tenancy strategies, value generation, and integrations with various technologies like spatial data and auditing. It highlights improvements in.hibernate ORM 4.3 and 5, such as custom annotations, built-in generators, and support for NoSQL with Hibernate OGM. Various modules like Hibernate Search for full-text queries and Hibernate Envers for versioning enhance data interaction and management in applications.
In this document
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Overview of Hibernate ORM capabilities and contributions by Brett Meyer.
Explains Object/Relational Mapping and the Java Persistence API (JPA) features.
Introduces multiple capabilities of Hibernate including Multi-Tenancy and Hibernate Search.
Details on multi-tenancy in Hibernate ORM, strategies, and how data isolation is achieved.
Discusses value generation enhancements in Hibernate, including methods for in-db and membrane generation.
Introduction to Hibernate Spatial, its capabilities, and how spatial data is handled using Geo types.
Examines Hibernate Envers for maintaining historical data and auditing features.
Introductory concepts on integrating Hibernate with OSGi for dynamic environments.
Describes utilizing Hibernate Search for efficient full-text search and indexing.
Briefs on Hibernate OGM for NoSQL support, Hibernate Validator for bean validation, and Shard strategies.
Information on how one can contribute to Hibernate ORM development.
Announcement for an upcoming session on tips, tricks, and performance prowess in Hibernate.
Session for questions regarding Hibernate ORM and contact info for reaching out.
Not Just ORM: Powerful Hibernate ORM Features and Capabilities
- 2. Not Just ORM: PowerfulHibernate ORM Features and Capabilities Brett Meyer Senior Software Engineer Hibernate ORM, Red Hat
- 3. Brett Meyer • HibernateORM – ORM 4 & 5 development – Hibernate OSGi – Developer community engagement – Red Hat support, Hibernate engineering lead • Other contributions – Apache Camel – Infinispan • Contact me – @brettemeyer or +brettmeyer – Freenode #hibernate or #hibernate-dev (brmeyer)
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- 5. ORM? JPA? • ORM:Object/Relational Mapping – Persistence: Data objects outlive the JVM app – Maps Java POJOs to relational databases – Supports OO concepts: inheritance, object identity, etc. – Navigate data by walking the object graph, not the explicit relational model • JPA: Java Persistence API • Hibernate ORM provides its own native API, in addition to full JPA support • Annotations and XML
- 6. Overview • • • • • • • • • Multi-Tenancy Value Generation Hibernate Spatial HibernateEnvers Hibernate OSGi Hibernate Search Hibernate OGM & Validator Hibernate Shards Ask questions after each section!
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- 8. Multi-Tenancy • • • • 1 ORM instance Multipleconcurrent clients Data specific to each tenant Legacy – Separate SessionFactories for each tenant – Application-provided Connections (given when opening a Session) – Big schemas or many tenants = huge footprint
- 9. Hibernate ORM Multi-Tenancy • • • • Strategy selectionis global Tenant identifier provided when opening a Session Works with 2LC: identifier used in cache data key Custom impls: – MultiTenantConnectionProvider: required for physical and schema separated (required) – CurrentTenantIdentifierResolver: required for opening a Session without providing the tenant id (explicitly or Session#getCurrentSession)
- 10. Hibernate ORM Multi-Tenancy Strategies •Physically separated databases – 1 JDBC connection pool per tenant – Pool selected based on tenant identifier • Single database, separate schemas – Option #1 • Similar to physically separated • 1 JDBC connection pool per tenant • Provides schema through the connection URL or pool – Option #2: • 1 JDBC connection pool using a default schema • Each Connection altered with SQL “SET SCHEMA” prior to use
- 11. Hibernate ORM Multi-Tenancy Strategies •Single database and schema – Data partitioned by discriminator value – Discriminator complexity varies – Each SQL statement altered to include the discriminator – Not yet implemented (planned for ORM 5) – Alternative: @FilterDef/@Filter w/ a tenantId as a param
- 12. Hibernate ORM Multi-Tenancy • DEMO •Questions?
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- 14. Value Generation (Legacy) •Limited to in-database value generation on insert/update • Properties marked with @Generated immediately selected
- 15. Hibernate ORM Value Generation • • • • New,expanded support in ORM 4.3 Supports legacy in-DB generation, but also in-mem Create custom annotations! ORM provides built in generators – @Generated: legacy, providing in-database generation – @CreationTimestamp: set only once when owning entity is saved for the first time – @UpdateTimestamp: set any time owning entity is saved – @GeneratorType: provide custom in-memory generator and define “when” • DEMO • Questions?
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- 17. Hibernate Spatial • Currently3rd party, but pulling in as a new ORM module in 5 • Originally created by Karel Maesen (geovise.com) • Java Topology Suite (JTS) – OpenGIS Simple Feature Spec (SFS) & SQL/MM Spatial (extends SFS) – Oracle, Postgres, MySQL, MS SQL, H2, etc. all implement the specs – Attempts to provide abstract, cross-platform geo data, but diffs between them • geolatte-geom – Developed/maintained by Karel – Improvement over JTS – Fully interoperable with JTS – Support for lat/lon geographies – Additional Dialect differences
- 18. Hibernate Spatial (cont'd) •Properties use JTS Geometry types – Point – LineString – Polygon – etc. • Adds HQL functions for Dialect-supported methods – Same functions also implemented as Criteria API Criterions – ex: "select e from Event e where within(e.location, :filter) = true" (:filter is a Geometry) – http://www.hibernatespatial.org/documentation/03-dialects/0 1-overview/
- 19. Hibernate Spatial (cont'd) •Translates between “Well-known text” (WKT) and Geometry types – Spatial object markup language – 2D and 3D – ex: “POINT (30 10)”, “POLYGON ((30 10, 40 40, 20 40, 10 20, 30 10))” • Coordinate system transformations possible in queries • Does not require JDBC extension drivers (ex: Oracle SDOAPI.jar or Postgres postgis.jar) • DEMO • Questions?
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- 21. Hibernate Envers • Provideshistorical versioning and auditing (“SCM for data”) • Each transaction == a “revision” • Revision #s are global --> querying for a historical snapshot of the entire database is possible • Requires – @Audited on the entity or individual properties – [entity]_AUD tables to store the historical data (DDL created automated if using hbm2ddl, otherwise it’s exportable) • Duplicate data? Yes. • Powerful queries/capabilities > cheap mem • Highly configurable
- 22. Hibernate Envers (cont'd) •Revision info – Default: simple internal entity stored in REVINFO table – Revision # and revision timestamp – Override with custom @RevisionEntity & RevisionListener (add other useful fields: IP address, “blame”, etc.) • Revision entity types – Track the entity types that were changed in each revision – Disabled by default: requires querying tables for changed data – Can be overridden by implementing EntityTrackingRevisionListener on your RevisionEntity
- 23. Hibernate Envers (cont'd) •Revision properties – Track the entity properties that were changed in each revision – Disabled by default: requires querying tables for changed data – Adds boolean columns to audit tables • Queries – Snapshot of entity states at a given revision (horizontal) – Revisions at which entities changed (vertical) • DEMO • Questions? • Conditional auditing – Default: Envers auditing reacts to Hibernate ORM events – Disable hibernate.listeners.envers.autoRegister, create your own listeners, wire them in using Integrator
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- 25. Hibernate OSGi • OSGi? •Provide only the OSGi manifest and hacky workarounds <-NO! • Emphasize doing things “the OSGi way” – Dynamic environment – Scoping • Limited visibility into the container • No scanning all bundles • Reduced conflicts, allows concurrent instances, etc. – OSGi services • Isolated in hibernate-osgi module (no pervasive dependencies or OSGi code)
- 26. Hibernate OSGi (cont'd) •3 supported environments – Enterprise OSGi Managed JPA • Container discovers and manages persistence units and EntityManagerFactories • Similar to many app servers, Spring, etc. • Ex: Apache Aries JPA – Un-managed JPA • Direct use of hibernate-entitymanager • EntityManagerFactories created through OSGi services – Native • Direct use of hibernate-core • SessionFactories created through OSGi services • Quickstarts • Questions?
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- 28. Hibernate Search • Full-textsearch on the DB – Bad performance – CPU/IO overhead • Offload full-text queries to Hibernate Search engine – Fully indexed – Horizontally scalable • Based on Apache Lucene • “Google for your entities”
- 29. Hibernate Search (cont'd) •Annotate entities with @Indexed • Annotate properties with @Field – Index the text: index=Index.YES – “Analyze” the text: analyze=Analyze.YES • • • • • Lucene analyzer Chunks sentences into words Lowercase all of them Exclude common words (“a”, “the”) Stemming
- 30. Hibernate OGM & HibernateValidator
- 31. Hibernate OGM &Validator • Hibernate OGM: – ORM/JPA support for NoSQL – Infinispan, EHCache, MongoDB, Neo4j • Hibernate Validator – Bean Validation impl, but extended – Both annotation and XML based – @NotNull, @Size(min = 2, max = 14), @Min(2), etc.
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- 33. Hibernate Shards • Startedas a Google team's 20% project • Horizontal partitioning across multiple databases • Flexible sharding strategies, both provided and custom • Supports virtual shards: simplifies re-sharding • Typical Hibernate ORM usage: HQL, Criteria, etc. • Last supported ORM version: 3.6.x • Currently has upgrade momentum – contact me if interested!
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- 35. Hibernate ORM: Tips, Tricks,and Performance Techniques Tomorrow, 1pm, Ballroom D
- 36. QUESTIONS? • • • • Q&A #hibernate or #hibernate-dev(brmeyer) @brettemeyer +brettmeyer