Sunday, December 2, 2018

Oracle Multitenant Enhancements in 18c - The Good and The Bad

Oracle Multitenant Option is the one of the most exciting enhancements in the Oracle Database probably in the last decade. It's definitely my favorite feature since 12c due to the elegant way it simplifies database consolidation projects. For more information about Oracle Multitenant, check out my blog post:

Oracle Multitenant 18c New Features - The Good
There are several nice Oracle Multitenant related enhancements in 18c which I believe worth mentioning in this blog post

  • Refreshable PDB Switchover - In Oracle 12c Release 2, Oracle introduced the refreshable PDB feature which allows to refresh a cloned PDB either on-demand or on a scheduled frequency. You can think of it as a poor-man standby because it's not designed for failover but more for having a cloned environment updated without having to completely clone the entire database every time (which may take a while). This could be very helpful for reporting/query offloading. Oracle 18c took this feature one step ahead and now enables to perform a switchover between the 2 PDBs which could be useful for load balancing purposes (planned switchover) as well as high availability when a PDB fails. Please note that this feature is not a replacement for data guard and should not be used as a DR solution for mission critical applications
  • Enhanced Data Guard Integration - In Oracle 12c, when Multitenant was configured in a data guard environment there were some challenges. Oracle 12cR2 introduced the hot clone feature which was a huge improvement as it allowed cloning a PDB with no downtime; however, when hot cloning a PDB, it was not performed on standby - in other words, it wasn't replicated also in the standby CDB (similar to specifying standbys=none). In Oracle 18c this challenge has been addressed by additional steps which required to be done. For more details, see:
  • Snapshot Carousel - Stores historical point in time copies of pluggable databases (up to 8 in the current 18c release). This is useful for historical debugging of data related issues as well as for point-in-time recovery of a PDB (similar to flashback database feature, but without enabling flashback database)
  • CDB Fleet Management - CDB allows to manage many PDBs as one (up to 4096 PDBs in Oracle Exadata and Oracle cloud, and 252 for every other deployment) - which is the main benefit of database consolidation. Now, in Oracle 18c using this new feature it's possible to manage many CDBs as one. I personally think this could be useful for the very large enterprise companies who manage huge amount of databases)

Oracle Multitenant 18c New Features - The Bad
According to Oracle documentation, all the above features (except the enhanced data guard integration), are only available either on Oracle Exadata or Oracle cloud. Most of the Oracle customers probably don't use neither Oracle Exadata nor Oracle cloud which makes these features unavailable for most Oracle customers. I hope this will be changed in the future.

Useful Links

Tuesday, October 9, 2018

Winning Performance Challenges in Oracle Standard Editions

Last week (on October 4th) I presented a webinar for IOUG titled "Winning Performance Challenges in Oracle Standard Editions". For those who missed the webinar a recording is available here:

Oracle Diagnostics and Tuning packs offer comprehensive valuable performance diagnostics and tuning features such as: AWR, ADDM, ASH, ASH Analytics, etc. These optional packs can be licensed only on top of the Oracle Enterprise Edition. Without these packs, diagnosing performance issues may become a very complex task – even for advanced DBAs. In this session we will explore how you could leverage Oracle’s Statspack report and dictionary views to diagnose performance issues even without using any expensive editions and packs.  In addition we will see how Quest tools can help DBAs to diagnose and solve even the most complex performance issues without relying on the Diagnostics and Tuning packs and for all the Oracle Database editions.

Slide Deck:
Slide deck is also available (

I'd like to thank everyone who attended and if you have any follow-up questions feel free to contact me (

Monday, April 30, 2018

IOUG Collaborate 2018 - Slide Decks are Available!

Last week I presented 3 sessions at my favorite Oracle conference - the IOUG Collaborate.
The slide decks for my presentations are now available:

Data Guard for Beginners
ASM Conepts, Architecture and Best Practices
Get the Oracle Performance Diagnostics Capabilities You Need without Spending a Fortune

I'd like to thank everybody who attended my sessions! Hope to see you again next year.

Saturday, February 24, 2018

RMOUG 18 Slide Decks - Now Available

Hi everybody,

This week I attended the RMOUG (Rocky Mountain Oracle User Group) conference in Denver, Colorado. It was my first time attending RMOUG and I must say that although it's not a very big event (I think around 350 attendees), I was very impressed by the quality of the event and the great content which was presented by very good speakers. I highly recommend it to anybody who considers attending next year's RMOUG. It's a great place to network, learn, and have fun.

I presented 2 sessions. The slide decks are now available:

I'd like to thank everybody who attended my sessions! Hope to see you again next year.

Sunday, January 28, 2018

ILOUG Tech Days 2018 Summary

Last week, ILOUG (Israel Oracle User Group) hosted an awesome Oracle conference in Israel which included 30 Oracle speakers from 9 countries and 45 different sessions.
This event was organized by Ami Aharonovich, Zohar Elkayam, and Oren Nakdimon, all good friends and Oracle ACEs.
It was a very well organized event, and awesome content which was delivered by 19(!) Oracle ACEs. In addition, there was a presence of Oracle Product Management as both Maria Colgan and Gerald Venzl attended and delivered several great sessions including an Oscar-candidate show of the IT Wars (DBA vs. Developer).
Also worth mentioning, Chris Saxon from Oracle presented an awesome SQL magic show :)

My session was about overcoming performance challenges when consolidating (pluggable) databases into a single Multitenant container. You can download my presentation here:

Thank you everyone who joined my session, and hope to see you again next year!