Performance Note Java Persistence and Hibernate

Performance Facts

• “More than half of application performance bottlenecks originate in the database - http://www.appdynamics.com/database/

• “Like us, our users place a lot of value in speed — that's why we've decided to take site speed into account in our search rankings.” Google Ranking

• “It has been reported that every 100ms of latency costs Amazon 1% of profit." http://radar.oreilly.com/2008/08/radar-theme-web-ops.html

JPA vs Hibernate

• JPA is only a specification. It describes the interfaces that the client operates with and the standard object-relational mapping metadata (annotations, XML).

• Although it implements the JPA specification, Hibernate retains its native API for both backward compatibility and to accommodate non-standard features.

HOW TO RUN THIS EXAMPLES

1. Postgres Data Base

First off all, we need to create a Postgres database with the name hibernate-tunings in the port 5432. For example, we can use Docker to create that resource:

docker run --name hibernate-tunings \
    -p 5432:5432 \
    -e POSTGRES_USER=postgres \
    -e POSTGRES_PASSWORD=postgres \
    -e POSTGRES_DB=postgresdemos \
    -v $(pwd)"/hibernate-tunings:/var/lib/postgresql/data" -d postgres:11.4

Or, simply run the docker-compose up command, which will raise a database and run the migrations for us:

docker-compose up

2. Run all modules in a single command

To run all modules in a single command, we can execute:

mvn flyway:migrate -pl database-migrations \
 -Dflyway.configFiles=local.conf \
 -Dflyway.locations=filesystem:database-migrations/migration \
&& mvn clean install -pl helpers \
&& mvn clean package

3. Run Step by Step

1. Run the migrations:

mvn flyway:migrate -pl database-migrations \
 -Dflyway.configFiles=local.conf \
 -Dflyway.locations=filesystem:database-migrations/migration

Or, in alternative:

cd database-migrations
mvn flyway:migrate -Dflyway.configFiles=local.conf

2. build and run all the examples.

mvn clean install -pl helpers && mvn clean package

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AGENDA

1. Get-Started

   1. logging-sql-statements

      • Typical causes of performance problems
      • Why We Need Logging
      • logging-sql-statements-examples

   2. schema-management

2. Connections

   1. Connection Manager
   2. Connection Lifecycle
      • JDBC Connection lifecycle
      • Lifecycle
   3. Hibernate Statistics

3. Types

   1. jpa-and-hibernate-types
   2. custom-hibernate-types
   3. open source hibernate types

4. Identifiers

   1. Generating Primary Keys
   2. Identifiers Generators and Natural Keys
   3. Hibernate Sequence Optimizers

5. JPA Relationships Types

   1. About
   2. Equals and Hashcode methods
   3. OneToMany and ManyToOne
   4. OneToOne Tradicional Bidimentional
   5. OneToOne Unidirectional with MapsId
   6. ManyToMany
   7. ElementCollection
   8. SecondaryTable

6. Inheritance

   1. SingleTable About
      • SingleTable Example
   2. DiscriminatorColumn
   3. JoinedInheritance with JoinTable

7. Persistence Context and Flushing

   1. PersistenceContext_Flushing
   2. ActionQueue
   3. AUTO FlushModeType
   4. Dirty-Checking
   • all the examples can be found in the module advanced-topics in the package: io.costax.hibernatetunning.persistencecontext

8. Batching

   1. Bash Updates Batch and Processing

9. Cache

   1. 1st and 2nd level and query caches
      • 1st level (Persistence Context)
      • 2nd Level
      • Query cache
   2. 2nd level cache in JavaEE Application Server Example with infinispan (cache2ndee project)

10. Bulk Operations

    1. Bulk Operation examples

11. Batching of write operations

    1. Batching-of-write-operations examples

12. Concurrency

    1. Concurrency About
    2. Isolation Issues
    3. Pessimistic Locking
       • LockModeType.PESSIMISTIC_READ
       • LockModeType.PESSIMISTIC_WRITE
    4. Optimistic-locking
       • @Version
       • Force Version Increment
    5. Timeout: javax.persistence.lock.timeout
    6. Deadlocks

13. Fetching

    1. Query Hint Fetch Size
    2. DTO Pagination
    3. NativeSQL Synchronized Entity Class
    4. Direct Fetching Entities
    5. Fetch Associations

14. Tips

    • How to map BLOBs and CLOBs with JPA and Hibernate

    • Soft delete

    • Enable Entity Listener for all entities

    • How Composite Identifier Automatically GeneratedValue

    • How map localized data with jpa

    • How to Join unrelated Entities

    • How to map a JPA entity to a View or SQL query using Hibernate

    • How to map an entity to multiple tables with SecondaryTable

    • How to solve the postgresql cast operator

    • How to use stored procedures

    • How to intercept entity changes with hibernate event listeners

    • How to load file properties lazy

    • How to map OneToOne fk in wrong side

    • How to use windows functions to optimise pagination

      • Fix HHH000104: firstResult/maxResults specified with collection fetch; applying in memory!

    • Enabling the hibernate.query.fail_on_pagination_over_collection_fetch configuration

      • Since Hibernate ORM 5.2.13, you can now enable the hibernate.query.fail_on_pagination_over_collection_fetch configuration property as follows:
      • Using JPA property <property name="hibernate.query.fail_on_pagination_over_collection_fetch" value="true"/>

    • Hibernate maven enhance plugin - enable Lazy Initialization

      • Fix N + 1 problem with hibernate-enhance-plugin
      • Impacts of enhance plugin on @ManyToOne relationship when this is marked with fetch=LAZY

    • How to exclude distinct keyword from the generated JPQL and Criteria Queries

    • What are the principal JPA and Hibernate Hints

    • How to enable hibernate query logging in Wildfly

    • How to use bytecode enhancement dirty checking with hibernate-enhance-maven-plugin

    • JPA 2.1-Standardized schema generation and data loading

    • How to Create An Entity Graph With Multiple Sub Graphs

    • How to use NotFound hibernate annotation, Action to do when an element is not found on a association

    • How to Join @ManyToOne of multiple subtypes in multiple collections in the same entity

    • How to implement a Hibernate ResultTransformer in JPA Criteria Query

    • How logging Hibernate slow query

      • <property name="hibernate.session.events.log.LOG_QUERIES_SLOWER_THAN_MS" value="25"/>

    • How to map OneToMany to a java.util.Map

    • Hibernate ToMany How to choice the right collection type

    • Localized Data – How to Map It With Hibernate

    • How to Fix OneToOne N+1 with manual enhance

    • How to keep Order in a Collections using javax.persistence.OrderColumn - JPA annotation

    • How to implement override value of the defined generator strategy

    • How to implement a custom application GenericGenerator for complex Identifiers

    • How to use Bean Validation In JPA Entities

    • Difference between @NotNull and @Column(nullable = false)

    • Hibernate 5 naming strategies

    • Xa Transactions (2-phase-commit)

    • How to map generated values

    • When and why JPA entities should implement the Serializable interface

    • The best way to use Java Records With JPA

    • How to Handle NULL Values while Ordering Query Results in JPQL (NULLS FIRST or NULLS LAST)

    • How to Implements business Custom Identifier Generator

    • How to override @GeneratedValue strategy with @GenericGenerator annotation

      • The defined business id it is used instead, instead of the value provides by @GeneratedValue.
      • The @GeneratedValue implementation should not be executed if the business identifier has already defined.

    • How to Map properties with database transformations using @ColumnTransformer hibernate annotation

    • How to fix MultipleBagFetchException

      • FixingMultipleBagFetchException

    • Hibernate SortNatural and SortComparator annotations

      • HibernateSortingTest

    • Batch Processing Best Practices With Jpa And Hibernate