Oracle Instance Memory Usage

How much memory does an Oracle instance actually use? How much does each individual database connection consume? ...

Survey Results: Why Do You Use RMAN Catalog DB for Your Oracle DB Backups?

SNAPSHOT CONTROLFILE Isn't Just a Backup Copy of a Control File Anymore

Recently, I have troubleshooted failing RMAN backups in 11.2.0.2 RAC environment. The backups failed with an error ...

Secrets of Oracle's Automatic Degree of Parallelism

Background: Automatic degree of parallelism, or Auto DOP, is a new feature in 11gR2 that promises to help manage ...

Oracle Database Appliance: Storage Performance -- Part 1

Today I want to show what kind of IO performance we can get from Oracle Database Appliance (ODA). In this part, I will ...

Oracle VM Manager: OVMAPI_6000E Internal Error: Connection Refused

Quick Update This is just a quick post to share my first 3.1.1 Oracle VM Manager (OVMM) troubleshooting experience. ...

Oracle Database Appliance -- Storage expansion with NFS (dNFS, HCC)

The biggest objection to Oracle Database Appliance (ODA) we hear from customers is about 4TB usable space limit ...

Linux Patching and Oracle: Detect RPM conflicts before they happen

A common scenario in the life of a DBA on a linux server looks something like this: From: Sue-the-sysadamin To:the-dba ...

Cursor: Pin S Wait on X in the Top 5 Wait Events

Lately, for some reason, I have started to come across the “cursor: pin S wait on X” wait event in the top 5 wait ...

Locks, Latches, Mutexes, and CPU Usage

I was alerted about a high CPU usage on a client machine. Checking which processes used the most CPU, I found that ...

DUPLICATE from ACTIVE Database Using RMAN, a Step-by-Step Guide

Duplicate using RMAN Recently, I had a request from one of our clients to duplicate a single instance database into a ...

Adaptive Log File Sync: Oracle, Please Don't Do That Again

Disclaimer: Much of what follows is pure speculation on my part. It could be completely wrong, and I'm putting it out ...

Getting GoldenGate Heartbeats Working with SUPPRESSTRIGGERS

Those of you who have seen me present about GoldenGate will know that I recommend using a heartbeat table to monitor ...

DBA_SCHEDULER_RUNNING_JOBS, where have you been?!

Backstory Where: Meeting room, Pythian office, Sydney, Australia. When: Afternoon, after lunch time. What: Discussion ...

Unofficial Oracle Database Appliance FAQ

Introduction I’ve started putting together some information about the Oracle Database Appliance in question-and-answer ...

Troubleshooting ORA-27090 Async I/O Errors with Systemtap

Last week, I ran into an issue on a high-volume Oracle database where sessions were periodically failing with ORA-27090 ...

Tools That Make Your Work with Oracle VM Easier

After completing your Oracle VM and Oracle VM Manager installation, you are ready to start your friendship with Oracle ...

Disabling Oracle triggers on a per-session basis

Update Jan-2014: I’ve added a note on disabling triggers in Oracle 11.2.0.4 Introduction I recently blogged about an ...

Repost: Oracle Protocol

On 18th May 2003, a man named Ian Redfern published a paper documenting the TNS protocol internals. The paper, entitled ...

Exadata Eighth Rack: A Few Thoughts

Oracle CEO Larry Ellison has announced the arrival of a new, smaller member of the Exadata X3 H2M2 family: the eighth ...

My SLOB IO Testing Index

Previous References ALL Pythian blog posts with Post Tag #SLOB My First Experience Running SLOB – Status Update 1 – or ...

RMAN duplicate in details

Its all started from the question on communities.oracle.com An “enhancement” in 11.2 prevents RMAN duplicating non ...

Oracle Direct NFS Configuration File Explained

While Oracle tech folks do their best to explain the meaning of not so many DNFS configuration file (oranfstab) ...

Exadata Patching Overview

Introduction Hello everyone ! For my first time posting here on the Pythian Blog, I would like to share some of my ...

Comparing Oracle Database Appliance and Exadata

Introduction Oracle Database Appliance (ODA) is in many ways similar to an Exadata quarter rack: they both use two ...

Oracle Direct NFS: How to Start

First of all, if you are using NFS to store Oracle database data files, I strongly advise you to enable Oracle Direct ...

Exadata Memory Expansion Kit

It’s always interesting to dig into the spec sheets for Exadata hardware, especially when those "minor" details like ...

Flashback and Forth

A reader of my previous post about Oracle’s Flashback Database posted a comment noting that the Oracle documentation ...

Introducing the Quarterly Database Patch for Exadata

Introduction Hot on the heels of 11.2.0.3 coming out for Exadata, there’s yet another Exadata patch schedule out: the ...