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PostgreSQL LogoPostgreSQL is an enterprise level open source database.

This is one of the most reliable, robust, feature-rich, and powerful relational database system.

Most importantly, PostgreSQL is well known for its ability to handle heavy load, and deliver high performance. This supports pretty much all the features that you would ever need from a RDBMS system.

If you are new to PostgreSQL, this tutorial will give you an excellent jump-start.
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How to SSH to AWS EC2 Instance from PuTTY using PEM Key Pair

In AWS, when you launch any EC2 Linux instance, you should select a key pair for that particular instance.

AWS key pair will be in the standard private key format with .pem file extension

But if you are using PuTTY on your Windows laptop to login to AWS instance, you have a problem.

PuTTY doesn’t support PEM format. PuTTY understands only it’s own PPK format.

PPK stands for Putty Private Key.
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8 Steps to Install MirthConnect with MySQL / MariaDB on Linux

Mirth Connect is an Open Source Integration Engine that is primarily used in the Health Care domain.

This support various health care standards (HL7, XML, EDI/X12, DICOM etc) that will help enterprise to integrate different systems, and let them talk to each other in a common language.

MirthConnect interface engine also supports various standard protocols (for example, TCP, HTTP, JDBS, SFTP, etc.) to connect two systems.

By default, when you install mirthconnect it uses Apache Derby as storage engine. But, it supports pretty much all popular databases including MySQL / MariaDB, PostgreSQL, Oracle and SQL Server.

In this tutorial, we’ll explain how to install MirthConnect open source software, and configure it to talk to MySQL database on Linux platform.
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5 Code Sign Examples and How to Install SignTool EXE on Windows

If you are a Linux sysadmin or a developer, you probably already know how to create and sign a SSL certificate for your webserver.

But, if your corporate environment also has some Windows servers and applications, you may end-up in a situation, where you may have to digitally sign Windows files.

The process of digitally signing a Windows files such as EXE, or DLL, or OCX, or CAB files is know as Code Signing.

For this, you should purchase a Code Sign certificate from a trusted provider like Symantec, or Thawte, or Godaddy, etc.

Once you purchase your code sign certificate, then you should sign your file using a tool called signtool.
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Once you’ve created your recipes and other objects for your chef cookbook, it should be uploaded to the Chef server.

There are two ways you can upload your cookbooks:

  1. Using knife cookbook sub-command – This helps you to manipulate your cookbooks
  2. Using knife upload sub-command – This helps you to upload all chef objects (including cookbooks, environments, nodes, etc.)

This tutorial explains how to use both of these sub-commands (knife cookbook and knife upload) with examples.
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7 Steps to Create New Oracle Database from Command Line

Oracle Create DBEven if you are a Linux sysadmin or developer, sometimes you might end-up managing Oracle database that is running in your environment.

In that case, it is essential to understand certain basic Oracle DBA activities. In this tutorial, we’ll explain how to create an Oracle database from command line.

When you install Oracle software, it will give you an option to create a new database from the UI.

At that time, if you decide not to create a new database, and install only the Oracle software, later you can create the database separately.
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The first hands-on Linux sysadmin workshop for this year is here. This time it will be conducted in Los Angeles for 2 days.

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How to Use C++ STL Queue with an Example Program

If you stand in a queue at a grocery store (or anywhere else), the first customer in the queue will be served, and then the next, and so on.

In programming terminology, especially in data structure, this concept is called FIFO (first in first out) queue.

In C++, Queue is an important part of a STL (Standard Template Library).

Apart from the typical FIFO queue, there are few other types of queue. For example, priority queue.

In a priority queue, apart from the FIFO characteristics, certain customers (or elements in a queue) might have a higher priority, and they might receive immediate service irrespective of their location in the queue.
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