[...] Aaron Brown highlights performance of MySQL Semi-Synchronous replication over high latency connections. [...]

This Log Buffer Edition is sparkling with fresh and budding blogs. This Log Buffer #280 is is encompassing Oracle, SQL Server and MySQL blogs. Please give your feedback in the comments. Enjoy Oracle: Kent Graziano shares the best practice about how to create the best data model ever. To compress or not to compress, Apun [...]

Tips to increase the performance of your MySQL queries. Use EXPLAIN on your queries EXPLAIN YOUR QUERY will show details of how mysql will execute your query. This is the first thing you should use if you got slow queries. Use the “Slow Query Log” to find the queries you have to optimize. If you don’t [...]

Read the original article at Juggling apples & oranges in the datacenter

In which a few choice words become one serious accident… The Backstory More than five years ago now, I worked for a shop in the business of news & information around the legal and real estate sectors. It was a fairly large organization with a number of Oracle and MySQL backed applications. The whole place [...]

For more articles like these go to Sean Hull's Scalable Startups

Related posts:

1. Open Insights 02 – Consulting Apples and Oranges
2. …

Last night we had a great audience at the Los Angeles MySQL Users Group. And it is not too late to RSVP for the meeting of San Diego PHP.

Some people want to use a backup to prepare a new Percona XtraDB Cluster node. They want this to avoid State Snapshot Transfer that could slow down the donor (depending of the SST method you are using, the donor can be blocked. I will cover this in a future blog post). As backup are generally performed during non-peak time, the effect should be reduced, and this avoid the need of performing 2 backups: the usual backup and the SST).

So to be able to use a backup for this purpose, we have 3 prerequisites:

• use XtraBackup >= 2.0.1
• the backup needs to be performed with –galera-info (option for innobackupex)
• have a gcache big enough to store all the changes from the time of the backup until the restore to be able to perform the Incremental State …

Mysql is the world’s most used open source relational database management system (RDBMS) that runs as a server providing multi-user access to a number of databases. The source code of MySQL has been made available under the terms of the GPL from the owner MySQL AB, which is now owned by Oracle Corporation. This, its [...]

I’m posting this because of a question raised against this older post on how to configure the %CLASSPATH% to find the ojdbc6.jar file. This is the lab file I use in my Database 1 class to expose students to the moving parts of writing Java programs against the Oracle database. That’s why I choose to use a CLOB data type, which requires Oracle’s DBMS_LOB package and wrapping stored procedures.

If you want the same content for MySQL, here’s the link. The full program in either blog entry is available by clicking on the fold/unfold Java Source Code Program widget at the bottom of the respective posts.

This demonstrates how to create an Java infrastructure for reading …

Benchmarking is a tricky thing, especially when it comes to compression. Some data compresses quite well while other data does not compress at all. Storing jpeg images in a BLOB column produces 0% compression, but storing the string “AAAAAAAAAAAAAAAAAAAA” in a VARCHAR(20) column produces extremely high (and unrealistic) compression numbers.

This week I was assisting a TokuDB customer understand the insertion performance of TokuDB versus InnoDB and MyISAM for their actual data. The table contained a single VARCHAR(50), multiple INTEGER, one SET, one DECIMAL, and a surrogate primary key.  To support a varied query workload they needed 6 indexes.

Here is an obfuscated schema of the table:

col1 varchar(50) NOT NULL,
col2 int(40) NOT NULL DEFAULT '0',
col3 int(10) NOT NULL DEFAULT '0',
col4 int(10) NOT NULL DEFAULT '0',
col5 int(10) NOT NULL DEFAULT '0',
col6 set('val1', 'val2', ..., ‘val19’, 'val20',) NOT NULL DEFAULT …

The release notes of MySQL 5.6.6  (http://dev.mysql.com/doc/refman/5.6/en/news-5-6-6.html) – probably to be released very soon – say  ”INSERT DELAYED is now deprecated, and will be removed in a future release”.

INSERT DELAYED had several problems (search bugs.mysql.com yourself).  IMO it always was a dirty solution substituting what should have been done 5+ years ago: change the protocol to allow ‘parallelism of multiple queries in a single connection’.  INSERT DELAYED worked around it in some scenarios as the execution of such query was ‘passed on’ to another thread.  But it was no real solution. We are still waiting for the real solution – true parallelism/multitasking in the client.

(MariaDB BTW has moved as far as possible in that direction without changing the protocol: A single client instance can …