Blog - Page 3 of 36 - Vlad Mihalcea

Posted on September 4, 2019 by vladmihalcea

How to get the SQL execution plan on Oracle

Last modified:

Introduction

In this article, we are going to see how we can get the SQL execution plan on Oracle.

When tuning performance, the execution plan is indispensable as it allows you to understand the operations done by the database when executing a certain SQL query.

4 Comments

Posted on August 27, 2019 by vladmihalcea

Mapping PostgreSQL Interval to Java Duration with Hibernate

Last modified:

Follow @vlad_mihalcea

Introduction

In this article, we are going to see how to map the PostgreSQL interval column type to a Java Duration object using Hibernate and the hibernate-types project.

Another very useful feature introduced by the hibernate-types project is that all types extending the ImmutableType can now be treated as standard org.hibernate.type.Type, therefore enabling a much better Hibernate Core API integration.

7 Comments

Posted on August 21, 2019 by vladmihalcea

How to map multiple JPA entities to one database table with Hibernate

Last modified:

Follow @vlad_mihalcea

Introduction

In this article, we are going to see how we can map multiple JPA entities to one table with Hibernate. Using multiple entities can speed up both read and write operations.

This question has been a recurring theme on StackOverflow, so I decided to explain the advantages of mapping multiple JPA entities to the same database table.

Leave a Comment

Posted on August 13, 2019 by vladmihalcea

How to limit the SQL query result set to Top-N rows only

Last modified:

Follow @vlad_mihalcea

Introduction

In this article, we are going to see how we can limit the SQL query result set to the Top-N rows only.

Limiting the SQL result set is very important when the underlying query could end up fetching a very large number of records, which can have a significant impact on application performance.

Leave a Comment

Posted on August 6, 2019 by vladmihalcea

How to write JPA Criteria API queries using Codota

Last modified:

Follow @vlad_mihalcea

Introduction

Writing JPA Criteria API queries is not very easy. The Codota IDE plugin can guide you on how to write such queries, which greatly simplifies the process.

In this article, we are going to see how Codota works and how it can help you discover a given API.

6 Comments

Posted on August 1, 2019 by vladmihalcea

Pagination best practices

Last modified:

Follow @vlad_mihalcea

Introduction

In this article, we are going to discuss several data pagination best and worst practices.

Data pagination is omnipresent in enterprise applications. Yet, most solutions, not only they offer a bad user experience, but they are also inefficient.

10 Comments

Posted on July 23, 2019 by vladmihalcea

SQL ORDER BY RANDOM

Last modified:

Follow @vlad_mihalcea

Introduction

In this article, we are going to see how we can sort an SQL query result set using an ORDER BY clause that takes a RANDOM function provided by a database-specific function.

This is a very handy trick, especially when you want to shuffle a given result set.

Leave a Comment

Posted on July 16, 2019 by vladmihalcea

How to override the default Hibernate Session FlushMode

Last modified:

Follow @vlad_mihalcea

Introduction

In this article, we are going to see how we can override the default FlushMode used by Hibernate.

If you bootstrap Hibernate natively, and not as a JPA provider, de default FlushMode.AUTO is used which, as explained in this article, does not trigger a Persistence Context flush prior to executing a native SQL query.

4 Comments

Posted on July 10, 2019 by vladmihalcea

Query timeout with JPA and Hibernate

Last modified:

Follow @vlad_mihalcea

Introduction

In this article, we are going to see what is the best way to set up the query timeout interval with JPA and Hibernate.

Setting the query timeout allows you to cancel slow-running queries that would, otherwise, put pressure on database resources.

Leave a Comment

Posted on July 3, 2019 by vladmihalcea

MySQL 8 support for custom SQL CHECK constraints

Last modified:

Follow @vlad_mihalcea

Introduction

In this article, we are going to test the MySQL 8 implementation of custom SQL CHECK constraints. Although the CHECK clause is a standard SQL feature, prior to MySQL 8.0.16, the clause was parsed and ignored, so this functionality could only be emulated via BEFORE INSERT and UPDATE triggers.

Vlad Mihalcea

How to get the SQL execution plan on Oracle

Introduction

Mapping PostgreSQL Interval to Java Duration with Hibernate

Introduction

How to map multiple JPA entities to one database table with Hibernate

Introduction

How to limit the SQL query result set to Top-N rows only

Introduction

How to write JPA Criteria API queries using Codota

Introduction

SQL ORDER BY RANDOM

Introduction

How to override the default Hibernate Session FlushMode

Introduction

Query timeout with JPA and Hibernate

Introduction

MySQL 8 support for custom SQL CHECK constraints

Introduction

Let’s connect

Find Article

Training and Workshops

eBook

Paperback Book

Video Course

Hypersistence Optimizer

SQL Training in Oslo

Tutorials

Consulting

Become a Java Champion

Sponsored

JPA and Hibernate Performance Tuning Tips

Tutorials

Social Media

About

Meta