I've noticed a trend lately.  In working with various organizations in the early stages of evaluating SaaS, I'm hearing vigorous defense of limitations. "We can't go to the cloud because our business is so unique."  "We can't consider cloud because our data is too complex to migrate." "We can't entrust our data to a 3rd party."  While there are plenty of additional reasons, I'm sure you've noticed the two important words forming (more...)

Connecting Hadoop and Oracle

Here are the slides of my yesterday’s OakTableWorld presentation. They also include a few hints about what our hot new venture Gluent is doing (although bigger annoucements come later this year).

[direct link]

Also, if you are at Oracle OpenWorld right now, my other presentation about SQL Monitoring in 12c is tomorrow at 3pm in Moscone South 103. See you there!


NB! After a 1.5 year break, this year’s only Advanced (more...)

API Management: Oracle’s vision from OOW

Being at Oracle Open World you get a chance to learn about Oracle’s vision and strategy directly. In this blog I’ll summarize some of the things I learned about Oracle’s vision on API Management from Oracle Product Management.

API management

API Management is becoming more and more important. Major drivers for this are the internet of things and the evolution of cloud solutions. API’s need to be accessible anytime, anywhere and from any application. Everything is (more...)

Introducing Oracle ASM Filter Driver

The Oracle ASMFD (Filter Driver) was introduced in Oracle Database and as of the moment it is available on Linux systems only.

Oracle ASM Filter Driver is a kernel module very much like the ASMLIB that resides in the I/O path of the Oracle ASM disks. It provides an interface between the Oracle binaries and the underlying operating environment.

Here are some of the features of ASMFD:

  • Reject non-Oracle I/O

The (more...)

My Oracle OpenWorld presentations

Oracle OpenWorld is just around the corner – I will have one presentation at OOW this year and another at the independent OTW event:

Connecting Oracle with Hadoop

Real-Time SQL Monitoring in Oracle Database 12c

  • Conference: OpenWorld
  • Time: Wednesday, 28 Oct, 3:00pm
  • Location: Moscone South 103
  • Abstract: Click here

I plan to hang out at the OTW venue on Monday and Tuesday, so see you (more...)

Log Buffer #446: A Carnival of the Vanities for DBAs

This Log Buffer Edition covers some more Oracle, SQL Server and MySQL blog posts from across the world.


  • Should I monitor the MGMTDB database?
  • Connecting MAF Applications to Mobile Cloud Service
  • JRE 6, 7, and 8 now certified with EBS 11i, 12.1, and 12.2
  • The database writer copies data blocks from the buffer cache onto disk. The db_writer_processes initialization parameter determines how many processes will do this task. Its default value is (more...)

Histogram Limit

A surprising question came up on OTN a couple of days ago:

Why does a query for “column = 999999999999999999” run slower than a query for “column > 999999999999999998” (that’s 18 digit numbers, if you don’t want to count them). With the equality predicate the query is very slow, with the range-based predicate perfomance is good.

In the absence of further information there are various reasons why this is possible – but the example in (more...)

Should I monitor the MGMTDB database?

During the installation of Oracle Grid Infrastructure you had the option to install the Grid Infrastructure Management Repository (GIMR) database MGMTDB. With, that option went away, and the MGMTDB database became mandatory. Given that it’s a database, the question of whether it should be monitored by Enterprise Manager was raised by a number of customers, and unfortunately a variety of different answers were forthcoming from different sources (more...)

Oracle OpenWorld 2015. Additional Attractions to Consider: OakTable World and EMC Rocks Oracle OpenWorld.

This is a quick blog entry to to share some information with readers who are attending Oracle OpenWorld 2015.

EMC Rocks Oracle OpenWorld

EMC has a concurrent event at the Elan Event Center (directly across the street from Moscone West) during OpenWorld. This event is a great opportunity to come see the most unique and powerful solutions and products EMC has to offer to folks using Oracle Database. You can register for the event at (more...)

Must See Session at This Year’s OOW

I’ve seen a lot of interesting posts about what’s going to be presented next week at OOW15, and I’ve blogged about those specific to Enterprise Manager previously – see the links Private Cloud and DBLM, Database Manageability and Middleware Management for more detail. But some people have come to me and said “There are so many sessions to go to for Oracle Open World, can you identify the must see session for what’s happening (more...)

Errors in a Pluggable Database?


There might be a situation where executing some DDL in pluggable database may cause the following error:

ORA-65040: operation not allowed from within a pluggable database

This error could occur if a tablespace is being dropped from within PDB and this tablespace is a former default tablespace having some of the system objects. Even system objects cannot be moved with simple alter statements from within PDBs.

So in order to move these objects from (more...)

People from Ireland who are Speaking at #OOW15

Oracle Open World 2015 will be kicking off in a few days time. There will be over 50K people attending this event, with a couple of hundred speakers.

I'm one of the lucky ones to have been selected to speak at Oracle Open World. This will be my third or fourth year in a row that I'm speaking at Oracle Open World.

Am I the only person from Ireland who is speaking at Oracle Open (more...)

Be the Change You Want to See

There is an incredible power with the simple act of doing.  People have a tendency to complain about the world, but there are only a few that refuse to simply accept it as it is and reach out to change it.

The Gift, The Anarchy

This video with the Red Pill Analytics guys, Stewart and Kevin, was a great opportunity to talk about something that is very important to folks like Jeremy Harms (more...)

SALE: Oracle SQL Developer Data Modeler Jump Start

So in honor of the upcoming #OOW15 and User Group Sunday Symposiums, I decided to put my video workshop for #SQLDevModeler on Sale! Why use #SQLDevModeler? If you were an Oracle Designer user and are looking for a replacement data modeling tool, or you are using one of the other mainstream, expensive modeling tools and […]

My schedule for OOW15

It seems to be a things that people blog about their schedule for Oracle Open World and talk about how busy they will be.

So to join the club this is my current schedule.


The boxes that are (a kind of) orange with red text are when I have MY presentations.

The purple boxes indicate some fun event and entertainment.

When attending conferences sometime you get to hear about a good presentation or some other (more...)

Why do you need to resetlogs after a cold backup restore

I posted a routine on how to take a cold backup locally to disk and then restore it back in 2010. Last week I was asked in a comment ‘why did you have to open the database using resetlogs?’  A very good question I thought so I proceeded to backup and recover just as the blog showed and I now know why.

Because Oracle will not let you do otherwise

Let me run through (more...)

Developer Cloud Service 15.4.1 is Now Available!

We are pleased to announce the release of Developer Cloud Service 15.4.1 with a number of new features. We'll keep it short and to the point!

  • Now available is cross-data center deployment for Java Cloud Service - SaaS Extension (JCS SX)
  • Support is now provided for Gradle (Open Source Build Automation)
  • Support for Oracle Maven Repo is now provided and available to DevCS Hudson executors
  • Import of on-premise Hudson job configurations into DevCS is now supported

Thanks to all #odevchoice voters!

And special thanks to all the great people who voted for me! :)
I want to list all voters for all nomenees in one page:

The query (using xt_http of course :) )

  finalists(category, userid, name) as (
      --                               SQL~ Voting:
      ------ ------------------ -------------------------------------------------------------------------------------
      select 'SQL'     , 6899,  'Stew Ashton      ' from dual union all
      select 'SQL'     , 6900,  'Sean Stuber      ' from dual union all
      select 'SQL'     , 6901,  'Sayan Malakshinov' from  (more...)

What AWR isn’t telling you

It is well-known that AWR, and Statspack before, take snapshots of V$ views (or rather the underlying objects) to produce the data in AWR.

It is also well-known that, when considering sql and its statistics in the shared pool, if something big hitting happens but the big-hitter is no longer in the shared pool by the time of the snapshot, then it can’t be recorded in your AWR picture of activity.

But like many things (more...)

OEM and monitoring the -MGMTDB GMIR Database

When you create Grid Infrastructure in, you are presented with a new (annoyingly named) “-MGMTDB”

This database is a standard, 12C CDB/PDB storing transient performance and other information. If it is lost, no biggie. Just re-create it (in your voting disk DG. Aside: create a new MGMTDB_DG, move your voting disk there, re-create -MGMTDB, then move your voting disk back out to the proper multiple voting volumes.)

However, Oracle Enterprise (more...)