Showing entries 4391 to 4400 of 22547
« 10 Newer Entries | 10 Older Entries »
Displaying posts with tag: MySQL (reset)
Network attacks on MySQL, Part 6: Loose ends

Backup traffic

After securing application-to-database and replication traffic, you should also do the same for backup traffic.

If you use Percona XtraBackup with streaming than you should use SSH to send your backup to a secure location. The same is true for MySQL Enterprise Backup. Also both have options to encrypt the backup itself. If you send your backup to a cloud service this is something you should really do, especially if it is not sent via SSH or HTTPS.

And mysqldump and mysqlbinlog both support SSL. And you could use GnuPG, OpenSSL, WinZIP or any other tool to encrypt it.

Sending credentials

You could try to force the client to send credentials elsewhere. This can be done if you can control the parameters to the mysql client. It reads the config from /etc/my.cnf, ~/.my.cnf and ~/.mylogin.conf but if you for example specify a login-path and a hostname.. it connects to that host, but with the …

[Read more]
Correct Index Choices for Equality + LIKE Query Optimization

As part of our support services, we do a lot of query optimization. This is where most performance gains come from. Here’s an example of the work we do.

Some days ago a customer arrived with the following table:

CREATE TABLE `infamous_table` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `member_id` int(11) NOT NULL DEFAULT '0',
  `email` varchar(200) NOT NULL DEFAULT '',
  `msg_type` varchar(255) NOT NULL DEFAULT '',
  `t2send` int(11) NOT NULL DEFAULT '0',
  `flag` char(1) NOT NULL DEFAULT '',
  `sent` varchar(100) NOT NULL DEFAULT '',
  PRIMARY KEY (`id`),
  KEY `f` (`flag`),
  KEY `email` (`email`),
  KEY `msg_type` (`msg_type`(5)),
  KEY `t_msg` (`t2send`,`msg_type`(5))
) ENGINE=InnoDB DEFAULT CHARSET=latin1

And a query that looked like this:

SELECT COUNT(*)
  FROM `infamous_table`
 WHERE `t2send` > 1234
   AND …
[Read more]
MySQL for Visual Studio 1.2.7 has been released

The MySQL Windows Experience Team is proud to announce the release of MySQL for Visual Studio 1.2.7. This is a maintenance release for 1.2.x. It can be used for production environments.

MySQL for Visual Studio is a product that includes all of the Visual Studio integration functionality to create and manage MySQL databases when developing .NET applications.

MySQL for Visual Studio is installed using the MySQL Installer for Windows which comes in 2 versions:

  • Full (352.8 MB) which includes a complete set of MySQL products with their binaries included in the downloaded bundle.
  • Web (1.7 MB – a network install) which will just pull MySQL for Visual Studio over the web and install it when run.

You can download MySQL Installer from our official Downloads page at …

[Read more]
Replication Features in MySQL 8.0.1

MySQL 8.0.1 has just been released with a wonderful set of features across the board. Specifically in replication, there is plenty of new and exciting functionality as well as performance improvements.  In this post I am going to summarize the replication features of this development milestone release.…

The MySQL 8.0.1 Milestone Release is available

The MySQL Development team is happy to announce our 8.0.1 development milestone release (DMR), now available for download at dev.mysql.com. (8.0.1 adds features to 8.0.0). The source code is available at GitHub. You can find the full list of changes and bug fixes in the 8.0.1 Release Notes.…

ProxySQL Rules: Do I Have Too Many?

In this blog post we are going to take a closer look at ProxySQL rules. How do they work, and how big is the performance impact of having many rules?

I would like to say thank you to Renè, who was willing to answer all my questions during my tests.

Overview

ProxySQL is heavily based on the query rules. We can set up ProxySQL without rules based only on the host groups, but if we want read/write splitting or sharding (or anything else) we need rules.

ProxySQL knows the SQL protocol and language, so we can easily create rules based on username, schema name and even on the query itself. We can write regular expressions that match the query digest. Let me show you an example:

insert into mysql_query_rules …
[Read more]
InnoDB Page Merging and Page Splitting

If you met one of the (few) MySQL consultants around the globe and asked him/her to review your queries and/or schemas, I am sure that he/she would tell you something regarding the importance of good primary key(s) design. Especially in the case of InnoDB, I’m sure they started to explain to you about index merges and page splits. These two notions are closely related to performance, and you should take this relationship into consideration when designing any index (not just PKs).

That may sound like mumbo jumbo to you, and you may be right. This is not easy stuff, especially when talking about internals. This is not something you deal with on a regular basis, and often you don’t want to deal with it at all.

But sometimes it’s a necessity. If so, this article is for you.

In this article, I want to shed some light in explaining some of the most unclear, behind the scenes operations in InnoDB: page index creation, …

[Read more]
InnoDB Page Merging and Page Splitting

If you met one of the (few) MySQL consultants around the globe and asked him/her to review your queries and/or schemas, I am sure that he/she would tell you something regarding the importance of good primary key(s) design. Especially in the case of InnoDB, I’m sure they started to explain to you about index merges and page splits. These two notions are closely related to performance, and you should take this relationship into consideration when designing any index (not just PKs).

That may sound like mumbo jumbo to you, and you may be right. This is not easy stuff, especially when talking about internals. This is not something you deal with on a regular basis, and often you don’t want to deal with it at all.

But sometimes it’s a necessity. If so, this article is for you.

In this article, I want to shed some light in explaining some of the most unclear, behind the scenes operations in InnoDB: page index …

[Read more]
Proposal to Change the Behavior of JSON_MERGE

In MySQL 5.7, one of the most popular new features is the introduction of JSON:

  1. The JSON data type
  2. A set of 20 functions to search, manipulate and create JSON documents
  3. Virtual Columns for JSON indexing

In MySQL 8.0 we plan to extend this functionality (for example: with the addition of JSON aggregate functions), but we are also considering changing the behaviour of one of the existing functions.…

Non-Deterministic Order for SELECT with LIMIT

In this blog, we’ll look at how queries in systems with parallel processing can return rows in a non-deterministic order (and how to fix it).

Short story:

Do not rely on the order of your rows if your query does not use

ORDER BY

. Even with

ORDER BY

, rows with the same values can be sorted differently. To fix this issue, always add

ORDER BY ... ID

 when you have

LIMIT N

.

Long story:

While playing with MariaDB ColumnStore and Yandex ClickHouse, I came across a very simple case. In MariaDB ColumnStore and …

[Read more]
Showing entries 4391 to 4400 of 22547
« 10 Newer Entries | 10 Older Entries »