Who never had to measure the disk performances on a system?

Speaking about Linux performance monitoring includes a significant part of disk performances. If you are facing applications or databases running slower than expected or than on other environments, you may take a look on the I/O performances.
This posting aims to provide an introduction to a pretty interesting tool: IOzone.

Last week, Oracle Ace Director Jonathan Lewis held an Oracle Optimizer Workshop at dbi services Basel Area. I would like to share some of the key learnings of this really interesting exchange I experienced together with my colleagues.

Oracle has introduced three new caching features in its Oracle 11g release:

• Query result cache
• Client OCI result cache
• PL/SQL function result cache

In this posting, I will present the query result cache feature.

I'm pretty sure that most of you already struggled with some low performance systems. In order to analyse such cases several tools and utilities, like top, nmon, fuser or lsof are available under Linux. However trying to dig in processes analysis and looking for files and processes relations may be quite painful.

To get started with performance checks and analysis, a interesting utility is available: htop

I have seen at a customer that SQL Server's policy doesn't follow Microsoft's recommendations about antivirus and databases (kb 309422), such as excluding *.mdf,*.ndf and *.ldf files. In addition, there is no Oracle policy in case of Forefront Endpoint Protection 2010 (known as FEP 2010).

I have decided to create generic databases policies for FEP (optimized by dbi services) adapted for all SQL Server and Oracle environments.

MySQL 5.6 offers improved partition maintenance through "partition exchange". Even if not yet available, dbi services performed some tests on the MySQL Community Edition 5.6.2 m5 release (still under development).

Sometimes, you need to modify the statistics of a table. There are various reasons: either for the performance analysis or because the execution plan changed. Oracle offers two methods: statistics restore or statistics export. Both are in the dbms_stats package.

Nowadays, MySQL Databases are encapsulated into many mission critical software solutions. Lots of companies host one or many MySQL databases in their data center, sometimes even without knowing it except when the MySQL service is not available anymore. In order to increase the service availability, it is mandatory to have a monitoring solution. Regardless of if you are using MySQL Server, MySQL replication or cluster, the Oracle/MySQL monitoring solution is called MySQL Enterprise Monitor.

Since Oracle 11.2, Oracle provides ORION in the RDBMS binaries (in ${ORACLE_HOME}/bin). ORION - ORacle Input Output Numbers - is an I/O calibration tool allowing to simulating and testing I/O performances an Oracle database would be confronted with. ORION basically supports four kinds of database activities based on either small or large I/O. ORION can, as any respectable I/O simulation tool, generate an adapted workload using a given percentage of reads and write operations.