Querying connection information in MongoDB

As with all other database platforms, daily administration and troubleshooting of MongoDB often begins with analyzing ...

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

Mystery Solved: Replication lag in InnoDB

Troubleshooting Replication Lag During XtraBackup While running a backup with XtraBackup against a slave server we ...

The Easy Way of Finding Similar SQL Statements

RMAN: Corrupt Block? Let's Re-Read... Nope, It's All Good

Getting a "corrupt block" page 40 minutes before your shift ends is the DBA equivalent of a jump-scare in a horror ...

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 ...

Read GoldenGate Discard Files

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 ...

Build an 11gR2 RAC Cluster in VirtualBox in 1 Hour Using OVM Templates

After reviewing my blog post about running EBS OVM templates in VirtualBox, two of my teammates suggested that I work ...

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 ...

EBS: R12 Default OACORE Memory Settings Are Not Enough

Not many of you know that my day-to-day work focus is Oracle E-Business Suite :). Here goes for an EBS-related blog ...

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 ...

How EBS Concurrent Processing Should Run on Oracle RAC

Suggested audience: Oracle Apps DBAs, Oracle e-Business Suite technical architects, and Oracle ATG team. Introduction ...

How to Troubleshoot OEM 12c Cloud Control Auto-Discovery

I was recently involved in an upgrade project to go from 11.2.0.2 to 11.2.0.3 on an Exadata V2. We hit some snags ...

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 ...

Repost: Oracle Protocol

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

Analyzing SQL Server Data File Anatomy

A database is a defined space stored in the system, grouping user objects. This space can be split into several files ...

Revealing the Hints Behind the Automatic SQL Tuning Advisor

Background A client recently supplied a list of 50+ SQL IDs that should receive SQL profiles, and I’ve been working ...

This is How You Disable AUTO_TASKs in 11G

I find myself forgetting how to disable Oracle AUTO_TASKs on a regular basis. Therefore, I have decided to document it ...

Sleuthing for Temporary Space Spendthrifts

I was recently looking at an issue where a large database server was running out of temp space. The issue had occurred ...

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 ...

Changing SID on a RAC Environment

This post is just a short note documenting a procedure that isn’t done frequently or described anywhere else (to my ...

Select Statement Generating Redo and Other Mysteries of Exadata

Like many good stories, this one also started with an innocent question from a customer: “I often check “SELECT ...

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) ...

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 ...

Flashback and Forth

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

Temporary Tablespaces: to BIGFILE or Not to BIGFILE

I saw a question on the OTN Exadata forum asking whether or not to use BIGFILE temporary tablespaces in an Exadata ...