DBA Lounge

Exadata Join Offloading in Action

One of the biggest selling features of Oracle’s flagship engineered system – Exadata – is the storage offloading capabilities. Storage offloading allows data to be filtered as soon as it is read from storage, reducing the amount of data that database hosts need to process. The storage layer is a shared-nothing MPP architecture and in…

Oracle Database Load Testing Tools – Overview

At Pythian’s internal forum, someone just asked the following question: “The team here is evaluating DB load testing tools (Hammerdb, Orion, SLOB, and Swingbench) and was wondering about our experience in using different tools and what is our opinion?” I have experience using some of the tools mentioned. Therefore, decided to answer using this public…

Hard Drive: Inner or Outer?

To be precise, I wonder if OUTERmost tracks of a spinning HDD are faster than INNERmost tracks. Should we put physical IO performance secretive data to OUTERmost parts of  the disk and less critical data to INNERmost parts as several vendors suggests? Well I couldn’t find a better solution than grabbing all HDDs I have and start testing :)

ODA Re-imaging Could Take Anywhere Between 20 and 120 Minutes

This blog posts explains why Oracle Database Appliances re-imaging process timing may vary from 20 to 120 minutes. There are a check in the ISO:/Extras/setupodaovm.sh script that have an issue. Until the bug is fixed a) you may face different ODA nodes’ re-imaging times b) to be on the safe side check if md devices’ re-synchronization process is finished by running “cat /proc/mdstat” command before running any business critical processes on your ODA.

The Importance of an Action Plan

When I started my work in IT, I used to be in a very small shop. And even though we had people in several places in the same state, everything used to be very centralized, and work was from 9 to 5. Since we were basically only 2 people , our action plan used to…

Opening the Door Without the Keys

This week, my DBA team fulfilled a request to restore 1 month old lost data.  A review of the RMAN backups showed that we indeed had a valid level 0 from the requested day, which was 33 days ago.  However, upon recovery, the necessary archive logs to bring the database to a consistent point were…

The Undocumented Status “M” of an RMAN Backup

It is not uncommon for Oracle to have something undocumented , and this is just another case of this ailment. We have a database in which we have two copies of the same backup: one kept in the FRA and the other in an external disk, which from time to time gets deleted from this…

MetaCPAN JavaScript API

Sometimes, it’s humongous revolutions. Most of the time, it’s itsy bitsy evolutionary steps. Today’s hack definitively sits in the second category, but I have the feeling that it’s a little dab of abstraction that is going to provide a lot of itch relief.

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