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Displaying posts with tag: Oracle (reset)
Topping the Charts Again: dbForge Studios Awarded G2 High Performer & Leader Fall 2021

More good news coming our way! It is inspiring to see that all the hard work we put into our products pays off as happy users and good reviews bring us more and more recognition on independent software reviewing platforms and marketplaces. Today, the products in question are dbForge Studios for MySQL and Oracle, which […]

The post Topping the Charts Again: dbForge Studios Awarded G2 High Performer & Leader Fall 2021 appeared first on Devart Blog.

Congratulating Marcelo Altmann on his Promotion to Oracle ACE!

We’re excited to share that Marcelo Altmann from the Percona Server Engineering Team has just been promoted from Oracle ACE Associate to Oracle ACE.

Congratulations!

The Oracle ACE Program recognizes and rewards community members for their technical contributions to the Oracle community.

Marcelo initially joined Percona as a senior support engineer in our global services organization, where he helped customers with running their MySQL-based environments. In early 2020, he joined our Server Engineering team and has been actively involved in the development of Percona Server for MySQL and Percona …

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Title Case Anyone?

Sometimes life is too surreal. Like when somebody says, “How do you get title case in an Oracle database?” That’s when you know three things about the individual, while suppressing laughter. They’re not very experienced with SQL, likely lazy, and don’t read the documentation.

I had a little fun with somebody today by taking them down a small rat-hole. “Oh, gosh … ” I said, “… let’s write a function for that.” Here’s the joke function, like:

CREATE OR REPLACE
FUNCTION title_case
( string VARCHAR2 ) RETURN VARCHAR2 IS
BEGIN
  /* Change upper case to title case. */
  RETURN UPPER(SUBSTR(string,1,1)) || LOWER(SUBSTR(string,2,LENGTH(string)));
END title_case;
/

Then, we tested it with a query from the pseudo dual table:

SELECT title_case('incredible') AS "Proper Name" FROM dual;

It returned:

Proper Name
----------
Incredible

Then, I said “Oh, that’s not his …

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Installing MySQL Database Service (MDS)

On a previous blog post, we saw how to create an account on the Oracle OCI using the Oracle Cloud Free Tier offer and then how to instal MySQL Server on the Compute instance.
Some weeks later, the new MySQL Database Service (MDS) was out and I can show you now how to install and configure it.

We are talking about the MySQL 8.0 Enterprise Edition on the on Oracle Generation 2 Cloud Infrastructure. For the moment it’s only available on some of the data regions (Frankfurt and London for the EMEA zone), but normally others will be activated …

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MySQL InnoDB Cluster Disaster Recovery contingency via a Group Replication Replica

Just recently, I have been asked to look into what a Disaster Recovery site for InnoDB Cluster would look like.

If you’re reading this, then I assume you’re familiar with what MySQL InnoDB Cluster is, and how it is configured, components, etc.

Reminder: InnoDB Cluster (Group Replication, Shell & Router) in version 8.0 has had serious improvements from 5.7. Please try it out.

So, given that, and given that we want to consider how best to fulfill the need, i.e. create a DR site for our InnoDB Cluster, let’s get started.

Basically I’ll be looking at the following scenario:

InnoDB Cluster Source site with a Group Replication Disaster Recovery Site.

Now, just before we get into the nitty-gritty, here’s the scope.

Life is already hard enough, so we want as much automated as possible, so, yes, InnoDB Cluster gets some of that done, but there are other parts we will still have …

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MySQL Linux to Windows

My students want to transfer their course setup MySQL files from the Linux VM that I provide to Microsoft Windows 10. This post explains how because I found a couple small errors in the Google’d posts they would most likely see.

The first step is required because when I didn’t assign a name or domain to the the Fedora VM, which allows it to run as localhost on any student machine. In tandem, I didn’t assign a static IP address but opted for dynamic IP assignment. That means, the first step to securely copy the files requires you to find the assigned IP address. You can do that with the following Linux command:

ifconfig -a | grep 'inet[[:blank:]]' | head -1 | cut -c 14-30

It would return something like:

192.168.147.198

After you have discovered the IP address, you need to download PuTTy from their web site because includes the pscp (PuTTy …

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Data migration from MySQL to Oracle server

Data migration is a tiresome task requiring a great deal of manual activity. In this article, we will examine how to migrate MySQL data to the Oracle server, using Data Export feature built-in dbForge for MySQL products. In the given worked example, we will move data from the actor table and the query result from […]

SQL EXISTS and NOT EXISTS

Introduction In this article, we are going to see how the SQL EXISTS operator works and when you should use it. Although the EXISTS operator has been available since SQL:86, the very first edition of the SQL Standard, I found that there are still many application developers who don’t realize how powerful SQL subquery expressions really are when it comes to filtering a given table based on a condition evaluated on a different table. Database table model Let’s assume we have the following two tables in our database, that form a one-to-many... Read More

The post SQL EXISTS and NOT EXISTS appeared first on Vlad Mihalcea.

A beginner’s guide to SQL CROSS JOIN

Introduction In this article, we are going to see how a CROSS JOIN works, and we will also make use of this SQL join type to build a poker card game. Database table model For our poker card game application, we have created the ranks and suits database tables: The ranks table defines the ranking of cards, as well as the name and symbol used for each card rank: The suits table describes the four possible categories used by the French playing cards: Cartesian product In the set theory, the Cartesian product... Read More

The post A beginner’s guide to SQL CROSS JOIN appeared first on Vlad Mihalcea.

A beginner’s guide to database deadlock

Introduction In this article, we are going to see how a deadlock can occur in a relational database system, and how Oracle, SQL Server, PostgreSQL, or MySQL recover from a deadlock situation. Database locking Relational database systems use various locks to guarantee transaction ACID properties. For instance, no matter what relational database system you are using, locks will always be acquired when modifying (e.g., UPDATE or DELETE) a certain table record. Without locking a row that was modified by a currently running transaction, Atomicity would be compromised. Using locking for controlling access... Read More

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