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Displaying posts with tag: sql (reset)
The Best Way to Host MySQL on Azure Cloud

Are you looking to get started with the world’s most popular open-source database, and wondering how you should setup your MySQL hosting? So many default to Amazon RDS, when MySQL performs exceptionally well on Azure Cloud. While Microsoft Azure does offer a managed solution, Azure Database, the solution has some major limitations you should know about before migrating your MySQL deployments. In this post, we outline the best way to host MySQL on Azure, including managed solutions, instance types, high availability replication, backup, and disk types to use to optimize your cloud database performance.

MySQL DBaaS vs. Self-Managed MySQL

The first thing to consider when weighing between self-management and a MySQL Database-as-a-Service …

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SQL Except Clause Example | Except Statement In SQL

SQL Except Clause Example | Except Statement In SQL is today’s topic. The SQL EXCEPT operator is used to combine two select statements, which in turn returns the row that is present in the first select statement and not in the second select statement. This Clause acts like a subtract operation that we perform in sets and Venn diagrams.

SQL Except Clause Example

In SQL, EXCEPT returns those tuples that are returned by the first SELECT operation, and not returned by the second SELECT operation.

#Pictorial Representation

 

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MySQL 8 support for custom SQL CHECK constraints

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. Custom SQL CHECK constraints As I explained in this article, custom SQL CHECK constraints are very useful to ensure non-nullability constraints for JPA entity subclass-specific attributes when using the SINGLE TABLE JPA inheritance strategy. To understand the problem, consider we have the... Read More

The post MySQL 8 support for custom SQL CHECK constraints appeared first on Vlad Mihalcea.

2019 Open Source Database Report: Top Databases, Public Cloud vs. On-Premise, Polyglot Persistence

Ready to transition from a commercial database to open source, and want to know which databases are most popular in 2019? Wondering whether an on-premise vs. public cloud vs. hybrid cloud infrastructure is best for your database strategy? Or, considering adding a new database to your application and want to see which combinations are most popular? We found all the answers you need at the Percona Live event last month, and broke down the insights into the following free trends reports:

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ScaleGrid DBaaS Expands MySQL Hosting Services Through AWS Cloud

PALO ALTO, Calif., June 6, 2019 – ScaleGrid, the Database-as-a-Service (DBaaS) leader in the SQL and NoSQL space, has announced the expansion of their fully managed MySQL Hosting services to support Amazon Web Services (AWS) cloud. The platform allows MySQL AWS administrators to automate their time-consuming database operations in the cloud and improve their performance with high availability, disaster recovery, polyglot persistence, and advanced monitoring and analytics.

Over the years, migrating data to the cloud has become a top priority for organizations looking to modernize their infrastructure for improved security, performance, and …

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Structuring Your Unstructured JSON data

The world seems awash in unstructured, NoSQL data, mainly of the JSON variety.  While this has a great many benefits as far as data mutability and not being locked into a rigid structure there are some things missing that are common in the structured world of SQL databases.

What if there was a way to take this unstructured NoSQL JSON data and cast it, temporarily, into a structured table?  Then you could use all the processing functions and features found in a relation database on you data.  There is a way and it is the JSON_TABLE function.

JSON_TABLE
You can find the documentation for JSON_TABLE here  but there are some examples below that may make learning this valuable function easier than the simple RTFM.

I will be using the world_x dataset for the next example

If …

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MySQL Tutorial – Managing MySQL Server Logs: Rotate, Compress, Retain & Delete

MySQL Server generates several logs that can help you monitor the activities of the server. However, once these logs are enabled, they can grow in size and start taking up too much disk space. This is why it’s important to have an automated way of archiving and preserving MySQL log files for a certain duration, as well as deleting the old ones. In this blog post, we describe some best practices for setting up and managing MySQL error logs, general logs and slow query logs for your MySQL deployments.

Setting Up MySQL Server Logging

Let’s look at how to setup the following 3 types of logs:

Error Log

Logs all the problems encountered during starting, running, or stopping mysqld. This log can be enabled by having the following option in /etc/my.cnf file:

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MySQL High Availability Framework Explained – Part III: Failure Scenarios

In this three-part blog series, we introduced a High Availability (HA) Framework for MySQL hosting in Part I, and discussed the details of MySQL semisynchronous replication in Part II. Now in Part III, we review how the framework handles some of the important MySQL failure scenarios and recovers to ensure high availability.

MySQL Failure Scenarios Scenario 1 – Master MySQL Goes Down

  • The Corosync and Pacemaker framework detects that the master MySQL is no longer available. Pacemaker demotes the master resource and tries …
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SQL Where Clause Example | SQL Where Query Tutorial

SQL Where Clause Example | SQL Where Query Tutorial is today’s topic. The WHERE clause is used to filter the database records. The WHERE clause is used to extract only those records that fulfill the specified condition. The SQL WHERE clause is used to specify the condition while fetching the data from a single table or by joining the multiple tables. If a given condition is satisfied, then only it returns the specific value from the table. You should use a WHERE clause to filter the records and fetching the necessary records.

SQL Where Clause Example

The WHERE clause is not only used in the SELECT statement; it is also used in an UPDATE, DELETE statement. The syntax of a SELECT statement with a WHERE clause is following.

SELECT column1, column2, columnN 
FROM table_name
WHERE [condition]

“SELECT column1, column2, column3 FROM tableName” is the standard …

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How does a relational database execute SQL statements and prepared statements

Introduction In this article, we are going to see how a relational database executes SQL statements and prepared statements. SQL statement lifecycle The main database modules responsible for processing a SQL statement are: the Parser, the Optimizer, the Executor. A SQL statement execution looks like in the following diagram. Parser The Parser checks the SQL statement and ensures its validity. The statements are verified both syntactically (the statement keywords must be properly spelled and following the SQL language guidelines) and semantically (the referenced tables and column do exist in the database). During... Read More

The post How does a relational database execute SQL statements and prepared statements appeared first on …

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