Showing entries 12271 to 12280 of 44137
« 10 Newer Entries | 10 Older Entries »
Another 10 Performance Wins

Following on from my earlier 10 performance wins post, here is another group of 10 I have worked on.

# Target Analyzed Key Tool Fixed Specific Improvement
11 redis System DTrace System scheduler 41%
12 rsync System DTrace Application app config 5x
13 mongoperf …
[Read more]
PERFORMANCE_SCHEMA vs Slow Query Log

A couple of weeks ago, shortly after Vadim wrote about Percona Cloud Tools and using Slow Query Log to capture the data, Mark Leith asked why don’t we just use Performance Schema instead? This is an interesting question and I think it deserves its own blog post to talk about.

First, I would say main reason for using Slow Query Log is compatibility. Basic Slow query log with microsecond query time precision is available starting in MySQL 5.1, while events_statements_summary_by_digest table was only added in MySQL 5.6 which was out for …

[Read more]
How TokuMX was Born

With TokuMX 1.4 coming out soon, with (teaser) wonderful improvements made to sharding and updates (and plenty of other goodies), I’ve recently reminisced about how we got TokuMX to this point. We (actually, really John) started dabbling with integrating Fractal Tree® indexes into MongoDB in the summer of 2012, where we (really, he) prototyped using Fractal Tree indexes only for secondary indexes. As cool as that

[Read more]
Overriding MySQL current_timestamp default on update

The MySQL TIMESTAMP data type supports automatic initialization and updating to the current date and time. This can be a convenient way to track when rows are created and modified, but it's easy to forget about them and have them update data when you don't want that. In those cases you need to explicitly set the column value to avoid the automatic behavior. On an update, that means setting the column to its current value. Quoting the manual:

If the column is auto-updated, it is automatically updated to the current timestamp when the value of any other column in the row is changed from its current value. The column remains unchanged if all other …

[Read more]
Creating Users & Granting Permissions in MySQL

One of the first tasks when setting up a new MySQL server is creating users and granting them permissions, or giving them the ability to do stuff in MySQL. By default, a single user, the root user, is created when you setup MySQL. This user is granted all privileges on the entire system, which means you should create separate logins for administrators and applications. Let’s walk through all the basic steps you need to create a new user and give them permissions.

Create a User

The first command I’ll show you is pretty simple:

Create User bob@'%' Identified By 'Astr0ngPhr@$e';

Before we move on, let’s check that user’s permissions:

Show Grants for bob@'%';

Which should show something like:

+----------------------------------------------------------------------------------------------------+
| Grants for bob@% …
[Read more]
MySQL Bulgarian users group ? Anybody interested ?

MySQL is widely used throughout the world. With users groups in many countries. In fact Oracle even tracks these on a wiki page.

Look at the map of Europe. See a pin missing ?

Would you be interested in filling it in ? Maybe we can gather and share MySQL related knowledge ? We do have some MySQL developers that are based in Bulgaria. And probably a lot of very advanced MySQL users too. All of us can benefit from talking to each other IMHO.

Please let me know if you'd be interested into gathering every now and then and talking MySQL. If there are people interested I'm sure we'll figure out the details.

EDIT : I've created a MySQL Bulgaria Meetup page.  Please feel free to sign up and start talking !

WITHer Recursive Queries?

Over the past few years, we’ve seen MySQL technology advance in leaps and bounds, especially when it comes to scalability. But by focusing on the internals of the storage engine for so long, MySQL has fallen behind regarding support for advanced SQL features.

SQLite, another popular open-source SQL database, just released version 3.8.3, including support for recursive SQL queries using the WITH RECURSIVE syntax, in compliance with SQL:1999.

Why is this significant? It means that MySQL is now the only widely-used SQL implementation that does not support recursive queries. Fifteen years after it was defined in the SQL standard, almost every other SQL database of note has supported this feature:

[Read more]
MaxScale - Just What Can It Do Today?

It seems that in all the writing around what MaxScale is, why I think we need it and what we plan to do with it, we have created some confusion as regards what it can do as of today, mid-February 2014. So I thought I would try to clear it up a little my writing this short post. The version that is described here is the one that is available from SkySQL download site and is labelled as version 0.4, later code is available in GitHub, with the changes we are working on, but I will not cause more confusion by referring to these.

Our design concept for MaxScale is a core with five plugin interfaces that provide different functionality, currently we have a core, that supports the event driven model we wanted, but we have only implemented three of the five plugin interfaces. The interfaces that have been implemented are the protocol plugin, the query router and the monitor.

The authentication mechanism we are using currently is …

[Read more]
HowTo Video: Exporting your database using MySQL for Visual Studio

MySQL for Visual Studio 1.1.3 introduced a new feature: MySQL Data Export tool. This tool allows the users to create a dump of an existing MySQL database. This video shows a quick tutorial on how to use this tool for creating MySQL exporting script inside Visual Studio.

MySQL 5.6.16 Community Release Notes

Thank you to the MySQL Community, on behalf of the MySQL team @ Oracle. Your bug reports, testcases and patches have helped create a better MySQL 5.6.16.

In particular:

  • Thanks to Honza Horak for suggesting we make tmpdir configurable at build-time, and for providing a patch. Bug #68338.
  • Thanks to Hartmut Holzgraefe for reporting a memory leak when using the InnoDB memcached API and replication. Bug #70757.
  • Thanks to Justin Swanhart for reporting that InnoDB reported an incorrect operating system error code when it failed to initialize. Bug #70867.
  • Thanks to Yoshinori Matsunobu who reported …
[Read more]
Showing entries 12271 to 12280 of 44137
« 10 Newer Entries | 10 Older Entries »