As always, this fresh Log Buffer Edition shares some of the unusual yet innovative and information-rich blog posts from across the realms of Oracle, SQL Server and MySQL.

Oracle:

A developer reported problems when running a CREATE OR REPLACE TYPE statement in a development database. It was failing with an ORA-00604 followed by an ORA-00001. These messages could be seen again and again in the alert log.

• Few Random Solaris Commands : intrstat, croinfo, dlstat, fmstat for Oracle DBA
• When to use Oracle Database In-Memory?
• Oracle Linux and Oracle VM at …

To lose your data or make it unavailable there is an excellent option in MySQL, rather than drop or delete Option name is lower_case_table_names. Default value of this setting is 0:

       mysql> select @@lower_case_table_names; 
       +--------------------------+ 
       | @@lower_case_table_names | 
       +--------------------------+
       | 0 | 
       +--------------------------+ 
       1 row in set (0.00 sec) 

Due to documentation value=0: Table and database names are stored on disk using the lettercase specified in the CREATE TABLE or CREATE DATABASE statement. Name comparisons are case sensitive. You should not set this variable to 0 if you are running MySQL on a system that has case-insensitive file names (such as Windows or OS X). If you force this variable to 0 with –lower-case-table-names=0 on a case-insensitive file system and access MyISAM tablenames using different …

Last week I wrote up my thoughts about the Percona acquisition of Tokutek from the perspective of TokuDB and TokuMX[se]. In this third blog of the trilogy I'll cover the acquisition and the future of the Fractal Tree Index. The Fractal Tree Index is the foundational technology upon which all Tokutek products are built.



 So what is a Fractal Tree Index? To quote the Wikipedia page:
"a Fractal Tree index is a tree data structure that keeps data sorted and allows searches and …

In a previous post, I wrote an overview about Spider for MySQL with its advantages and disadvantages. Now I’ll go through a simple example demonstrating how to implement Spider for MySQL.

System information: MySQL instances information (shards):

• Server: 3 VMs (here in after will be mentioned as mysqla “192.168.56.51”, mysqlb “192.168.56.52” and mysqlc “192.168.56.53”).
• OS: CentOS 6.4
• RAM: 512MB
• MySQL version: 5.5.43 (tar-balls)
• Download link: http://dev.mysql.com/get/Downloads/MySQL-5.5/mysql-5.5.43-linux2.6-x86_64.tar.gz

…

Mon, 2015-05-04 10:58ralfgebhardt

The MariaDB Audit Plugin has been included in MariaDB Server by default since version 5.5.37 and 10.0.9. It's also pre-loaded in MariaDB Enterprise. The Audit Plugin as of version 1.2.0 includes new filtering options which are very useful. This article explains some aspects of them. However, if you haven't installed and used the plugin, you may want to read first a few other documents:

• Activating Auditing for MariaDB and MySQL in 5 Minutes
• MariaDB Audit Plugin – Set Up a Remote Log File using rsyslog
• …

This blog post is a follow up to our previous post on monitoring CPU-related InnoDB metrics in Galera Cluster. 

One of the main issues in terms of scalability of MySQL (and thereby also Galera) is the ability to handle large amounts of I/O activity. MySQL, historically, was not very good in this area - flushing caused bumps and spikes in the workload, and kernel mutex was wrecking havoc in the overall stability. I/O handling changed in MySQL 5.5 and has been improved even further in MySQL 5.6. Multiple background threads for I/O, adaptive approach to flushing data, splitting the kernel mutex into a number of new mutexes and rw-locks. Even with all those changes, checking MySQL I/O metrics is a very important part of the daily routine.

How InnoDB saves data …

MySQL replication isn’t perfect and sometimes our data gets out of sync, either by a failure in replication or human intervention. We are all familiar with Percona Toolkit’s pt-table-checksum and pt-table-sync to help us check and fix data inconsistencies – but imagine the following scenario where we mix regular replication with the Tungsten Replicator:

We have regular replication going from master (db1) to 4 slaves (db2, db3, db4 and db5), but also we find that db3 is also master of db4 and db5 using Tungsten replication for 1 database called test. This setup is currently working this way because it was deployed some time ago when multi-source replication was not possible using regular MySQL replication. This is now a working feature in …

The VividCortex brainiacs continue taking strides toward better database monitoring, one feature at a time. See our 2015 highlights here and contact us to see how we can improve your IT efficiency.

Restore hackmysql.com/case1: Indexing Basic MySQL Queries.

This is a new release with some new features and many bugfixes and enhancements.

Get it from the download page.



Changelog:
* New feature: Add support for JSON grid export
* New feature: Add support for Markdown Here grid export
* New feature: Support new command line parameter "n", or "nettype", which takes an integer, representing the protocol number (0=mysql tcpip, ...).
* New feature: Add support for connecting to Microsoft Azure Servers
* New feature: Add edit box + updown buttons for limiting the size of exported INSERT queries in bytes.
* New feature: Display creation time, last alter time, comment and start time of scheduled events.
* New feature: Online help document …