Replication is one of the basic and most essential feature available in MySQL. Replication allows you to maintain additional copy of database on another server and keep itself updated with latest changes in master databases. Having another copy of data (other than backup) is always a good option. In case of any issues on master server we can always failover to slave and make it a master. This provides high availability. You can have (more...)
What is GTID ?
GTID stands for Global Transaction Identifier. This is a new feature introduced in 5.6 version.
I have given a link in reference section of this article which explains the concept of GTID.
Global transaction identifier is a unique transaction ID assigned to every transaction that happens in MySQL database. This ID has specific importance in maintaining replication slave. Using this ID we can easily track which transactions has been applied to (more...)
MySQL utilities are set of scripts provided for DBAs for general database administration. These are basically command line utilities which can be used to perform various tasks.
Following is the listing of MySQL utility version 1.3 that I installed in my environment
advait.desktop$ ls -lL /usr/local/bin/mysql*
-rwxr-xr-x 1 root root 10546 Mar 26 00:34 /usr/local/bin/mysqlauditadmin
-rwxr-xr-x 1 root root 13443 Mar 26 00:34 /usr/local/bin/mysqlauditgrep
-rwxr-xr-x 1 root root 10142 Mar 26 00:34 /usr/local/bin/mysqldbcompare
Having noticed the release of PHP 5.5.10
last week while I was speaking at UTOUG, I checked the deprecated
mysqli functions web page
. There weren’t any deprecated by 5.5. Unfortuantely, there were six
functions deprecated in 5.4, and many of my posted code examples use 5.3. The deprecated
Unfortunately, that puts a lot of updates on my queue of things (more...)
Shantanu asked a follow-up question on my Cleanup a MySQL Schema post from last month. He wanted to know if there was a way to capture foreign keys before removing them. The answer is yes, but how you do it depends on whether the primary key is a surrogate key using an auto incrementing sequence of a natural key using descriptive columns.
You can capture foreign keys with a simple query when they’re determined by (more...)
I am exploring another database storage solution “MySQL” to understand practical applications of using MySQL in our environment.
This is one of the many articles that I will be writing on MySQL. This article gives you brief steps to installing MySQL on Linux.
Nothing different than what is provided in MySQL documentation except that this is less elaborate with only required steps compared to MySQL documentation.
This is how you can do the installation:-
Today new version of JSON UDF functions: 0.2.1 was released. This is maintenance release which added no new functionality and only contains bug fixes. However, it also includes improvements for build ans test procedures. As usual, you can download source and binary packages at MySQL Labs. Binary packages (more…)
Relational DBMS used to be fairly straightforward product suites, which boiled down to:
- A big SQL interpreter.
- A bunch of administrative and operational tools.
- Some very optional add-ons, often including an application development tool.
Now, however, most RDBMS are sold as part of something bigger.
Sometimes people want to connect to MySQL from Oracle and copy table data between the databases. You can do that with Oracle Hetrogenous Services via ODBC. This post will show how to create an odbc connection to your MySQL database which is the first part of this.
For my example, (more...)
I find myself installing and running mysql of different versions in different places for different reasons all the time (well often enough to do it and not remember the little things that cost time when setting up) Its with that in mind, I'm making notes for myself and you (more...)
I lampoon the word “disruptive” for being badly overused. On the other hand, I often refer to the concept myself. Perhaps I should clarify.
You probably know that the modern concept of disruption comes from Clayton Christensen, specifically in The Innovator’s Dilemma and its sequel, The Innovator’s Solution. The basic (more...)
When Steven and I wrote MySQL Stored Procedure programming our biggest reservation about the new stored procedure language was the lack of support for proper error handling. The lack of the SIGNAL and RESIGNAL clauses prevented a programmer from raising an error that could be propagated throughout a call (more...)
I got a question a while ago that I thought was quite simple, but turned into an interesting discussion: How much hard disk space does a database take up?
As it happens, there's a simple answer and a much, much more involved (yet ill-defined) answer, and which one you choose (more...)
The ALTER TABLE statement syntax is explained in the manual at:
To put it simply, there are two ways you can alter the table to use a new character set.
1. ALTER TABLE tablename DEFAULT CHARACTER SET utf8;
This will alter the table to use (more...)
Replication is a hot topic in MySQL 5.6, and for good reason: There are many excellent features that make it a strong well-supported feature, from the new Global Transaction Identifiers (GTIDs), to simplified replication configuration and automated failover using MySQL Utilities (now available in alpha as a separate download (more...)
For my newest ipython-sql trick, I needed to compare some queries run across different databases. How hard would it be to get side-by-side results into tidy IPython Notebook output?
Not hard at all, it turns out, if you're willing to violate basic principles of human decency.
That's an itty-bitty image, (more...)
I talked Friday with Deep Information Sciences, makers of DeepDB. Much like TokuDB — albeit with different technical strategies — DeepDB is a single-server DBMS in the form of a MySQL engine, whose technology is concentrated around writing indexes quickly. That said:
- DeepDB’s indexes can help you with analytic queries; (more...)
Some time ago I wrote a blog post describing a way I use to verify MySQL Server bugs. But my job consists not only of bugs which can be verified just by passing SQL queries to the server.
One of such examples is UDF bugs.
MySQL User Reference Manual is (more...)
If you're considering using MySQL Cluster, you might be tempted to try it out on one of your existing databases. MySQL Cluster 7.3 (available as a development release at the time of this post) supports foreign keys, so it seems sensible to try migrating an InnoDB database (more...)