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Category Archives: Application integration & Middleware

Hervé Schweitzer

A SQL statement is slow and suddenly fast? Have a look at “Cardinality Feedback”!

By | Application integration & Middleware | 2 Comments

Discussing with some tuning gourous we were made aware about this feature. It is not so far from the adaptive cursor sharing perfectly described in  Chris’s blog : http://antognini.ch/papers/BindVariablePeeking_20090718.pdf

This feature, compares the real execution (number of returned/actual rows “A-rows”) with some expectations (number of expected rows “E-rows”) and chooses another plan for the next executions if the difference between the expectation and the actual result is too big. “Cardinality Feedback” is not well documented in the Oracle documentation.

 
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Grégory Steulet

Simulating and testing I/O performances with ORION

By | Application integration & Middleware | One Comment

Since Oracle 11.2, Oracle provides ORION in the RDBMS binaries (in ${ORACLE_HOME}/bin). ORION 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.

 
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Yann Neuhaus

Simulating database-like I/O activity with Flexible I/O

By | Application integration & Middleware | No Comments

You do not want to install or configure swingbench, load runner etc. – just to test the performance of your I/O system based on filesystems? Then Flexible I/O is the right tool for you. This post provides an overview. In order to simulate Oracle database I/O workload on filesystems, ORION cannot be used since it only uses raw or block devices (scratching the filesystem). To simulate Oracle database I/O behaviour on filesystems, we can use…

 
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Grégory Steulet

MySQL Workbench 5.2: changing the life of MySQL developers and DBAs

By | Application integration & Middleware | 2 Comments

MySQL Workbench provides several necessary tools in order to manage a MySQL environment. MySQL Workbench 5.2 is available for Windows, Mac and Linux platforms, it encapsulates three main functionalities:

1.    SQL Development: Allows connecting to existing databases and run SQL Queries, SQL scripts, edit data and manage database objects. This functionality replaces the ones previously provided by the Query Browser stand-alone application.

2.    Data Modeling: Helps to create and manage models, allows forward & reverse engineering and provides capability to compare and synchronize schemas

3.    Server Administration: Helps to configure a database server, to setup user accounts and browse status variables and server logs

 

Let’s have a look deeper in each of those features:

 
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