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On RDBMS, NoSQL and NewSQL databases. Interview with John Ryan

“The single most important lesson I’ve learned is to keep it simple. I find designers sometimes deliver over-complex, generic solutions that could (in theory) do anything, but in reality are remarkably difficult to operate, and often misunderstood.”–John Ryan

I have interviewed John Ryan, Data Warehouse Solution Architect (Director) at UBS.

RVZ

Q1. You are an experienced Data Warehouse architect, designer and developer. What are the main lessons you have learned in your career?

John Ryan: The single most important lesson I’ve learned is to keep it simple. I find designers sometimes deliver over-complex, generic solutions that could (in theory) do anything, but in reality are remarkably difficult to operate, and often misunderstood. I believe this stems from a lack of understanding of the …

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MySQL 8.0 : more about new authentication plugin and replication

MySQL 8.0’s new default authentication plugin means more secure connections for users connections but also for replication… but you need to be aware of it !

Yesterday Giuseppe – the datacharmer – Maxia, submitted a bug related to a strange behavior of MySQL’s replication.

He observed that after creating a new user for replication (using the new authentication method, caching_sha2_password), when he created the slave as usual, replication was not starting… Slave_IO_Running was constantly in “Connecting” and the Last_IO_Error was:

Last_IO_Error: error connecting to master 'repl2@127.0.0.1:24011' - …
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Binlog Encryption with Percona Server for MySQL

In this blog post, we’ll look at how to turn on binlog encryption in Percona Server for MySQL.

Why do I need this?

As you probably know, Percona Server for MySQL’s binlog contains sensitive information. Replication uses the binlog to copy events between servers. They contain all the information from one server so that it can be applied on another. In other words, if somebody has access to a binlog, it means they have access to all the data in the server. Moreover, said person (or, “Hacker”) could create a clone copy of our server by just making a replica of it. In the end, they have access to our binlog. This shows how important protecting a binlog really is – leakage of binlogs not only make a particular table/tablespace or a group of tables accessible to a hacker, but literally the whole server …

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Migrating MySQL Users to Amazon RDS

In this blog post, we’ll look at what is needed when migrating MySQL users to Amazon RDS. We’ll discuss how we can transform MySQL user grants and make them compatible with Amazon RDS.

In order to deliver a managed service experience, Amazon RDS does not provide shell access to the underlying operating system. It also restricts access to certain procedures that require advanced privileges.

Every MySQL instance has some users with ALL PRIVILEGES, and you can’t directly migrate these users to Amazon RDS because it does not support following privileges for regular users.

  • SUPER – Enable use of other administrative operations such as CHANGE MASTER TO, KILL, PURGE BINARY …
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MySQL – Foreign keys and “Cannot delete or update a parent row: a foreign key constraint fails” error

As you know, foreign keys establish a sort of relationship between 2 tables. MySQL requires InnoDB storage engine to support foreign keys.

In our example, we have the following parent table in a MySQL 5.7.21 server:

mysqld3-(root@localhost) [sakila]> show create table actor\G
*************************** 1. row ***************************
       Table: actor
Create Table: CREATE TABLE `actor` (
  `actor_id` smallint(5) unsigned NOT NULL AUTO_INCREMENT,
  `first_name` varchar(45) NOT NULL,
  `last_name` varchar(45) NOT NULL,
  `last_update` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`actor_id`),
  KEY `idx_actor_last_name` (`last_name`)
) ENGINE=InnoDB AUTO_INCREMENT=201 DEFAULT CHARSET=utf8
1 row in set (0.00 sec)

 

and a foreign key is defined on the child table by using the “FOREIGN KEY… REFERENCES” syntax:

mysqld3-(root@localhost) [sakila]> show create …
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Comparison of Window Functions & CTEs in MySQL 8 vs MariaDB

Every MySQL database programmer should learn and apply the newly added MariaDB and MySQL Window Functions and Common Table Expressions(CTEs) in their daily work. Both CTEs and window functions enable easy solutions to many query challenges that in prior releases have been difficult and sometimes impossible to surmount. Mastering these features opens the door to query solutions that are more robust, execute faster, and are easier to maintain over time than prior solutions using older techniques.

In our last blog we compared User Roles in MySQL 8 vs. MariaDB.  Today, we will here compare Window Functions and Common Table Expressions in both databases.

Window Functions

While all database administrators are familiar with aggregate functions like COUNT(), SUM(), and AVG(), far less people make use of window functions in their queries.  Unlike aggregate functions, which operate on an entire table, window …

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Preparing your Community Connector for MySQL 8 – part 2 – SHA256

In part 1 of this series we looked at implementing support for the caching_sha2_password authentication plugin using the libmyqlclient C library.  This is possible for C based connectors or connectors that can make use of an external C library.  For some, this is not possible.  For example, Java and C# both function better if they don’t have to thunk out to an external library.  For these, implementing the MySQL client/server protocol natively is required.  This part 2 is about implementing support for the caching_sha2_password plugin natively.  It is expected that you already have a working connector and understand the client/server protocol.  For reference please internal documentation …

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Webinar: Audit Log Analysis for MySQL & MariaDB Databases

Join Shree Nair, Product Manager at Webyog, as he demonstrates the new ‘Audit Log Analysis’ feature introduced in Monyog v8.5.0 and rolls out the roadmap for the upcoming releases.

Date & Time: Wednesday, March 21, 2018 at 11:00 am EDT

Register Now!

What to expect from the webinar?

– Quick walkthrough of Audit Log feature on a live Monyog instance.

– You will learn about the upcoming product roadmap for Monyog.

– You can take part in Q&A session and submit your feature requests too.

If you can’t attend this webinar live, register anyway and we’ll send you a link to the recording.

You can …

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MySQL 8.0 : Data Locking Visibility

With MySQL 8.0, engineers improved the visibility of data locking. Usually it was not that easy to deal with the output of SHOW ENGINE INNODB STATUS and mixing Information_Schema tables like INNODB_LOCKS and INNODB_LOCK_WAITS.

So in MySQL 8.0 we instrument data locks in Performance_Schema and we changed the SYS Schema view related to the InnoDB Locks Wait too.

This means that when a transaction A is locking row R, and transaction B is waiting on this very same row, B is effectively blocked by A. What we added is extra instrumentation to expose which data is locked (R), who owns the lock (A), and who is waiting for the data (B).

Testing

Let’s have a look at this simple scenario in MySQL 5.7.21 and 8.0.4 to compare:

2 clients starting a …

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MySQL Security – Password Management

Some regulations required that the password is renewed in a timely and appropriate manner (e.g. every 90 days). In this article, 2nd of the MySQL 5.7 Security series, we will see how to to establish a policy for password expiration with MySQL 5.7 Password Management.

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