Oracle 12c Moving Datafile Online
Contributions, Oracle

Oracle 12c – Moving Datafile Online

This is one of the tedious jobs which every DBA needs to perform at some point in time due to:

  • Insufficient Disk Space
  • Move from Non-ASM to ASM disk


Prior to Oracle 12c, it was a challenge for DBAs to perform this activity because clients always want minimal downtime, plus it requires additional database activities to be performed. (For example, Issue of some OS command followed by database commands.)

In order to understand the ease of this process, let’s see what DBAs needs to do to move a datafile prior 12c.

Continue Reading…

Performance Tuning Approaches Oracle
Contributions, Health Check, Linux, Oracle

Performance Tuning Approaches (Oracle)

An understanding of systems architecture and design provides the foundation for a proactive monitoring stance, but there is no better prevention than a periodic health check. Whether you accomplish this with OraChk, AWR reporting, or Statspack, regular inspection of a database is the most effective way of preventing issues before they happen.

Server issues (memory, CPU, and network bandwidth) all affect system performance. But how can you differentiate those from SQL performance issues, requiring different strategies and scope in the diagnostic phase?

Continue Reading…

Cloud, Contributions, Oracle

Back-up to Cloud

Over the last few years, a proliferation of web services paved the way for saving enterprise back-ups. Oracle recently added the Oracle secure back-up (OSB) cloud module to its inventory of back-up solutions, which allows RMAN to write database back-ups directly to the Amazon storage cloud. It offers all the major features of RMAN and provides a cost-effective alternative to tape and online storage. This document highlights some of the steps involved in configuring RMAN backup to the Amazon cloud.


OS: OSB is currently supported on Linux & Window platforms.

JAVA: JDK 1.5 or higher is required to run the cloud module to configure the environment.

Note: Typically Oracle database 11gR2 installation may contain Java 1.5 JDK. This can be used in case the server doesn’t have the appropriate JDK installed. JDK location under Oracle home –

Continue Reading…

A Quick and Simple Way to Measure the I/O
Contributions, Oracle

A Quick and Simple Way to Measure the I/O

The following post highlights the use of Oracle’s in-built I/O performance tool introduced in 11gR1. It is a part of the DBMS_RESOURCE_MANAGER (CALIBRATE_IO procedure) PL/SQL package. Though this post may not provide the complete picture of I/O in every respect, it is useful to quickly understand the maximum sustainable IOPs and average latency, particularly for OLTP workloads. Understanding the latency for single block reads is quite important since it directly impacts the performance of transaction-based queries that make use of index reads.

A few points:

  • Make sure ‘timed_statistics’ is true (there is no need for further changes if statistics_level is ‘typical’).
  • Set ‘filesystemio_options’ to either setall or async (restart of the instance may be required)
  • Run this process during off-hours since it will generate I/O and to avoid mix-ups with other things going on in the database.
  • If RAC is used, make sure all instances are up and running.

Continue Reading…