Java Connect to to Derby Database in Network Client Mode (Eclipse)

Learn to use Apache Derby database in network client/server mode and how to code a Derby client program in Java with JDBC. Here's what you will learn in details:
- Download a distribution of Derby database
- Create a new Derby database and table using ij tool
- Start Derby database server
- Code a Derby client program using JDBC that connects to Derby server and executes SQL Insertn and Select statements (in a normal Java project as well as in a Maven project).
- Enable authentication and remote connections for Derby database server.

#java #apache

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Buddha Community

Java Connect to to Derby Database in Network Client Mode (Eclipse)

Tyrique Littel

1600135200

How to Install OpenJDK 11 on CentOS 8

What is OpenJDK?

OpenJDk or Open Java Development Kit is a free, open-source framework of the Java Platform, Standard Edition (or Java SE). It contains the virtual machine, the Java Class Library, and the Java compiler. The difference between the Oracle OpenJDK and Oracle JDK is that OpenJDK is a source code reference point for the open-source model. Simultaneously, the Oracle JDK is a continuation or advanced model of the OpenJDK, which is not open source and requires a license to use.

In this article, we will be installing OpenJDK on Centos 8.

#tutorials #alternatives #centos #centos 8 #configuration #dnf #frameworks #java #java development kit #java ee #java environment variables #java framework #java jdk #java jre #java platform #java sdk #java se #jdk #jre #open java development kit #open source #openjdk #openjdk 11 #openjdk 8 #openjdk runtime environment

Destiny Volkman

1597222800

PostgreSQL Connection Pooling: Part 4 – PgBouncer vs. Pgpool-II

In our previous posts in this series, we spoke at length about using PgBouncer and Pgpool-II , the connection pool architecture and pros and cons of leveraging one for your PostgreSQL deployment. In our final post, we will put them head-to-head in a detailed feature comparison and compare the results of PgBouncer vs. Pgpool-II performance for your PostgreSQL hosting !

The bottom line – Pgpool-II is a great tool if you need load-balancing and high availability. Connection pooling is almost a bonus you get alongside. PgBouncer does only one thing, but does it really well. If the objective is to limit the number of connections and reduce resource consumption, PgBouncer wins hands down.

It is also perfectly fine to use both PgBouncer and Pgpool-II in a chain – you can have a PgBouncer to provide connection pooling, which talks to a Pgpool-II instance that provides high availability and load balancing. This gives you the best of both worlds!

PostgreSQL Connection Pooling: Part 4 – PgBouncer vs. Pgpool-II

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Performance Testing

While PgBouncer may seem to be the better option in theory, theory can often be misleading. So, we pitted the two connection poolers head-to-head, using the standard pgbench tool, to see which one provides better transactions per second throughput through a benchmark test. For good measure, we ran the same tests without a connection pooler too.

Testing Conditions

All of the PostgreSQL benchmark tests were run under the following conditions:

Initialized pgbench using a scale factor of 100.
Disabled auto-vacuuming on the PostgreSQL instance to prevent interference.
No other workload was working at the time.
Used the default pgbench script to run the tests.
Used default settings for both PgBouncer and Pgpool-II, except max_children*. All PostgreSQL limits were also set to their defaults.
All tests ran as a single thread, on a single-CPU, 2-core machine, for a duration of 5 minutes.
Forced pgbench to create a new connection for each transaction using the -C option. This emulates modern web application workloads and is the whole reason to use a pooler!

We ran each iteration for 5 minutes to ensure any noise averaged out. Here is how the middleware was installed:

For PgBouncer, we installed it on the same box as the PostgreSQL server(s). This is the configuration we use in our managed PostgreSQL clusters. Since PgBouncer is a very light-weight process, installing it on the box has no impact on overall performance.
For Pgpool-II, we tested both when the Pgpool-II instance was installed on the same machine as PostgreSQL (on box column), and when it was installed on a different machine (off box column). As expected, the performance is much better when Pgpool-II is off the box as it doesn’t have to compete with the PostgreSQL server for resources.

Throughput Benchmark

Here are the transactions per second (TPS) results for each scenario across a range of number of clients:

#database #developer #performance #postgresql #connection control #connection pooler #connection pooler performance #connection queue #high availability #load balancing #number of connections #performance testing #pgbench #pgbouncer #pgbouncer and pgpool-ii #pgbouncer vs pgpool #pgpool-ii #pooling modes #postgresql connection pooling #postgresql limits #resource consumption #throughput benchmark #transactions per second #without pooling

Samanta Moore

1620458875

Going Beyond Java 8: Local Variable Type Inference (var) - DZone Java

According to some surveys, such as JetBrains’s great survey, Java 8 is currently the most used version of Java, despite being a 2014 release.

What you are reading is one in a series of articles titled ‘Going beyond Java 8,’ inspired by the contents of my book, Java for Aliens. These articles will guide you step-by-step through the most important features introduced to the language, starting from version 9. The aim is to make you aware of how important it is to move forward from Java 8, explaining the enormous advantages that the latest versions of the language offer.

In this article, we will talk about the most important new feature introduced with Java 10. Officially called local variable type inference, this feature is better known as the **introduction of the word **var. Despite the complicated name, it is actually quite a simple feature to use. However, some observations need to be made before we can see the impact that the introduction of the word var has on other pre-existing characteristics.

#java #java 11 #java 10 #java 12 #var #java 14 #java 13 #java 15 #verbosity

Seamus Quitzon

1603759531

Registration Form in Java Applet with Database Connectivity.

Summer Camp Registration Form is a program where the student has to fill his/her details in the respective fields mentioned in the form and register to participate in the camp for the same. It also discusses the implementation of the source code and database connectivity using Apache derby, and then focuses on Graphic User Interface(GUI), describing how the form is validated and the programming functions and libraries used in the design.

Programming Environment

**_Java Language: _**It is a general purpose programming language that is class-based, object-oriented (although not a pure object-oriented language, as it contains primitive types, and designed to have as few implementation dependencies as possible.

It is intended to let application developers write once,run anywhere(WORA), meaning that compiled Java code can run on all platforms that support Java without the need for recompilation.

Java applications are typically compiled to byte code that can run on any Java Virtual Machine (JVM) regardless of the underlying computer architecture. The syntax of Java is similar to C and C++, but it has fewer low-level facilities than either of them.

As of this year, Java was one of the most popular programming languages, according to GITHUB, particularly for client-server web-applications, with a reported 9 million developers.

Applet: A Java applet was a small application written in the Java programming language, or another programming language that compiles to Java byte code, and delivered to users in the form of Java byte code.

NetBeans IDE 8.2: NetBeans is a free, open-source cross-platform IDE that supports multiple compilers including GCC.

Apache Derby: Apache Derby, an Apache DB subproject, is an open source relational database implemented entirely in Java and available under the Apache License ,version 2.0.

#netbeans #derby #java #database #java-applet

Darrion Kerluke

1636747200