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Archive for the ‘UKOUG’ Category

Another really enjoyable UKOUG Database SIG

Posted by John Hallas on May 8, 2014

Today’s venue was the Metropole Hotel in the centre of Leeds and there was a good attendance, encouraged by a strong agenda.

After introductions, health and safety and UKOUG information it was straight into techie talk with Phil Davies from Oracle doing his normal support update (although he does share duties with Owen Ireland). Invariably I make more notes from this session than most others I hear because of the wealth of information it contains. Snippets I jotted down that are worthy of sharing are :- RDBMS is due out Jul-Dec 2014 and is likely to contain new functionality that did not get into the first 12c release – I think in-memory will be one such feature. A straw poll of members saw very little uptake of 12c in production and some but not much take-up in non-production.

Oracle Clud Control (OEM) is due very soon – Q2 2014

I was intrigued enough about MoS note 1557478.1 about a bug with transparent huge pages to make a note of it for further investigation and the same goes for 17761775.8 – Bug 17761775  ORA-600 [kclchkblkdma_3] ORA-600 [3020] or ORA-600 [kcbchg1_16] Join of temp and permanent table in RAC might lead to corruption

Next up was Phil Brown of E-DBA who ran an open forum where the audience picked from a selection of topics.

The three topics covered in about 70 minutes were

1)      Consolidation v Virtualisation

2)      The worst SQL statement in the world

3)      DBA interviews


All three allowed plenty of audience participation and competing views and I think almost everyone in the room provided input. My input regarding DBA interviews was a tip given to me several years ago which I think is very valid. Even if you are not thinking of moving on keep updating your CV so it is an accurate record of what you have been doing over the last couple of years. Read the rest of this entry »


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UKOUG – Tech13 – day 3 review

Posted by John Hallas on December 5, 2013

Another busy day at the Manchester Central complex. An early start with Martin Nash talking about RAC connectivity issues and bugettes. Very interesting but I don’t think my brain was fully in gear at 08:30 after a big hotel breakfast.

Straight into another two-man CERN presentation on Lost Writes. The first half was  about a scenario they had seen where an index has lost some data and frankly there was no explanation for what caused it to happen. However the second part was around how you might deal with the scenario and that was very good and gave a lot of food for thought.

Jonathan Lewis then spoke for an hour about histograms and how they had developed in 12c. There were some really good points made but I suspect he lost some of the audience about half way through – including myself – I did notice a man in front of me who was doing a Sudoku throughout the presentation.

I did my AWR talk and felt it went OK but because there was no time to talk to anyone afterwards and as I did not get  much audience feedback it was quite hard to judge how well it went. The first time  I did it was at a SIG and I think the low-key, less time-pressured environment suited the talk much  more than the conference.

That was the end of the conference for me. I caught up with a  couple of people and then made my way home. All in all it was a very well run conference and the Manchester venue was better than Birmingham in my opinion.  I really cannot see the exhibition carrying on though. I did not look at one stand and I suspect there were many others who did not either. I cannot see what  the exhibitors got out of it.

I must mention the entertainment on Tuesday  evening which was a drinks reception sponsored by Enkitec and Delphix at the National Football Museum. I was very pleased to get my photograph taken holding the actual ball used in the 1966 World Cup Final. I think everyone was asked to wear gloves but it might just have been me!!


Posted in 12c new features, Oracle, UKOUG | Tagged: , , , | 3 Comments »

UKOUG Tech13 – day 2 review

Posted by John Hallas on December 4, 2013

UKOUG conference day 2 opened up with Tom Kyte talking about 5 PL/SQL things you probably didn’t know. It did have 12c in the title but I think 4 out of the 5 were pre 12C. Implicit conversions are EVIL is my main take-away and he made me aware of the power of the PL/SQL warning framework to highlight any implicit conversions and other no-nos. Another important warning was when you code a WHEN OTHERS statement but do not follow it with a RAISE statement. Overall, an interesting discussion which I enjoyed despite only having ever written about 200 lines of code in my whole life.

Larry Carpenter then talked about new Active Dataguard new features in 12C. To be honest I could not see a use for most of them at my current workplace but they were obviously delivered to meet a demand. One feature was DataGuard Fast Sync and that seemed to be available when using normal (inactive??) DG on 12c so it might be something to look at. Larry also mentioned that Oracle would be announcing g a database backup appliance in the near future.

Two roundtables followed, both of which were a bit like the curate’s egg – good in parts.

The first was around Oracle’s OEM offering. I was hoping it would be a meeting where the audience shared some good things they had discovered about OEM (around 60% of the 30 strong audience were on 12c OEM). My humble offerings might have documentation  which provides as list of all the views on the sysman tables used to manage OEM.

However it really turned out to be of benefit to the two Oracle product managers in attendance as they just soaked up a list of issues from the audience – licensing difficulties and poor documentation mostly. There was one good tip on the help capability. If you type in backup or whatever else you want help on in the field on the home page where you put the target name in that will take you to help functionality that quite often has a direct link to the right page to get started.

One comment from the Oracle people was that they had an OEM channel on YouTube with 71 videos on it. All very good but anybody running a significant estate from OEM is probably a corporate and they are likely to have YouTube blocked at work. Nothing to stop you looking at home of course but it did seem a bit of a contradiction to me.

Then a three way round table on virtualisation that involved Microsoft, VMware and Oracle. The surprising thing was that they seemed to agree that the real benefit, above cost was agility. In fact they all seemed to agree on everything, especially the fact that there was no reason why the whole enterprise could not be virtualised. I raised the point that why would  I risk putting a Tier 1 Oracle RAC database on virtual when Oracle state that in the event of a problem they might insist on getting it on physical before they could help further. I think I was seen as a Luddite with my head buried in the sand. However, given that it could take days to provision a physical RAC environment and get a copy database deployed how could I justify that to management. Microsoft and VMware said they would have their own level 2 /3 support who would help out but that is hardly the same as working with the main supplier.

Lunch was spent talking to a friend around disk latencies, , UKOUG and Apex. An enjoyable and productive 45 minutes.

In the afternoon the best talk was by Pythian’s very enthusiastic Marc Fielding on Private cloud.  A few thoughts struck me on the container database and pluggable databases. Firstly it seems to be where SQLServer has been for years. The idea that you get try one pluggable database without licensing is bizarre because most of the things you would wish to test require more than one PBD. My two overall questions would be around memory management and security. With a single SGA that is not resource managed how does one stop one PBD filling the buffer cache after running FTS or producing a fragmented library cache with multiple parsing of sql – if you flush the shared pool does it do it across all the databases in the container. My main concern would be around security, a user on one PBD would be able to see the sql-text and v$session views of another PBD and therefore see data. I have not investigated CPD or PDBs at all so I don’t have the answers but I will be looking at it shortly.

Posted in 12c new features, Oracle, UKOUG | Tagged: , | 2 Comments »

UKOUG Tech13 day 1 review

Posted by John Hallas on December 3, 2013

UKOUG conference day 1 and to my eye there does not seem to be that many differences between Manchester Central and Birmingham ICC.  Lots of smaller halls and a large main hall,  a similar lunch available, the same lack of seating. I understand that attendance is seen comparable as well. Overall I see it as a refreshing change which will suit some and not others.  Make or break is the quality of the drinks do later on – that will be reported on tomorrow.

An early start for a standing room only talk by Carl Dudley on Flashback in 11g and 12c. A really good handout was provided, which negated the need to attend the presentation. Nice factual presentation of the capabilities and options of recovering data. Would have been nice to have seen a bit more real-world ideas and examples but a session that I would recommend downloading the paper later.

Andy Colvin of Enkitec talked about 12C RMAN new features. He covered recovery of a table from an RMAN backup and I proposed my unproven theory that it might be possible to use the functionality in 11GR2 (using the 12c binaries) and he suggested trying it in – the story continues. He also mentioned the role SYSBACKUP which takes away the need for the RMAN user to have select any table privilege. Someone in the audience stated that you might not have permission to read a table before you do a restore but you will afterwards which proved to be true. Looks like an Oracle bug. I think Andy learnt as much as the audience did. An hour well spent.

I did attend a presentation which I walked out of. I felt that the presenter was divulging too much about poor practises / long turnarounds at companies which he named. He then went into blatant advertising mode. Out I walked.

Then the CERN people were talking about latency. Lots of examples which were very good and some demos of a few tools they have created and seem to be publicly available. Well worth searching out. However I do not understand the concept of people sharing a presentation. Quite frankly one of the presenters added little value, perhaps it was a way of getting more speaker badges.

I also went to another CERN talk by David Wojcik on Cardinality feedback in 12C. This had the potential of being interesting but it was much too rushed and I doubt many in the audience came away much better informed. It was a pity because I think the slides are worthy of download and review.

My last one of the day was Martin Bach doing a non-technical presentation  – shock and horror. This was about how to manage engineered systems (or Exadata if you are in the Oracle world). An interesting and challenging talk and one that I really enjoyed. I did take issue with him re one of his recommendations and that started off what was quite a lively chat afterwards with most of the audience remaining.

Oh and the Manchester climate was quite mild, compared with ice and snow that I have suffered in Birmingham in recent years.

My final thought. Walking back to my hotel I saw a pub called The Ape and Apple. That must be worthy of some research as to what the name signifies and how it came about.

Posted in Oracle, RMAN, UKOUG | Tagged: , , | Leave a Comment »

Ready for UKOUG Tech13

Posted by John Hallas on November 27, 2013

I have downloaded the agenda app for UKOUG Tech 13 – Mon 2nd – Wed 4th December in  Manchester and I have selected the talks I want to attend.

Primarily they are from the database streams with a bit of Engineered systems (Exadata for me) thrown in. Undoubtedly the release of 12C has generated many of the talks and that is all very good – exactly what the conference is there for – to find out what is new and which new features work well or can be adopted easily with real benefit.

I am disappointed that my talk has not been made the keynote speech but there is always next year. Only joshing

I am speaking at 11:30 about building and managing of an AWR repository. In a way I wish I had tried to do 2 talks , one on implementing the system and the other on what you could do with it. That is the part that really enthuses me and I feel I could generate a  talking shop around those ideas for the whole session. Bring it on I say. It is a pity I am up against Niall Lichfield and Martin Bach, both very experienced professionals and good presenters. However my consolation is knowing how upset they will be about not being able to attend my talk. 🙂

Overall the agenda looks very strong and I am attending on all 3 days – not the Sunday though. It certainly looks full on starting at 09:00 on the Monday and running through until tea-time on the Wednesday

I think my only surprise is Tom Kyte is giving a keynote speech late on the last day and I suspect that he will not be that well-attended as people start to drift off home. I hope I am proved wrong.

I have been doing a bit of a Movember so I am posting a current photo. Mind you the growth might be gone by Monday as we will be into December then.


Posted in UKOUG | 5 Comments »

UKOUG featured speaker of the week – AWR presentation

Posted by John Hallas on November 4, 2013

I am speaking at the UK Oracle User Group  conference in Manchester on Weds 4th December on the subject of building and using an AWR repository but I also include the capture and long-term retention of OEM data as well.I have given this talk once already to a SIG and it got very good feedback and I have developed the ideas significantly since then.

I am also pleased to say that I have been selected as featured speaker of the week at the UKOUG site.  Caution – it does include my photograph.

The conference is normally held in Birmingham but is moving to Manchester for the first time this year. Another change is that Wednesday has a full agenda now, normally it tails off after lunch. I think the UKOUG conference is a must go to anybody who is looking for new ideas and techniques or even just to remind themselves of best practise.

The agenda is excellent  and I can see many difficult decisions on which talks to attend. I do know that whatever I decide then I will come away with a bunch of notes and follow-up ideas which will keep me busy for the next few months.

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UKOUG Conference here I come

Posted by John Hallas on August 19, 2013

I am pleased to say that I have been offered at a slot at the UKOUG Tech conference to present my paper on “The design, creation and maintenance of an AWR repository”. I have presented this once already to a SIG meeting and I felt it went down well and the feedback and comments I received afterwards supported that and allowed me to develop the ideas further.

The big day is Weds 4th December at the new venue in Manchester. For those of you who are used to the Birmingham event it should be pointed out that this year Wednesday will be a full day of presentations comparable with both Monday and Tuesday and not the half-day, wind-down that we have seen in recent years.

The formal agenda will be launched in September but for now the dates and venue are :-

UKOUG Technology Conference 2013 2nd – 4th December 2013 at the Manchester Central Convention Complex.

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Building an AWR repository – UKOUG SIG presentation

Posted by John Hallas on July 10, 2013

I am pleased to be presenting at the UKOUG AIM and Database SIG  in London on Thursday 18th July. I am talking about building and using an AWR repository.

My precis reads This talk will cover the whole process of managing an AWR repository that will take feeds from many databases for long-term retention and analysis. It will cover the reasons to do this, how to size the repository and then how to move AWR snapshots into the repository. The management of the repository including partitioning advice, compression and gathering of statistics as well as how to housekeep the AWR repository will also be covered.

This presentation will be of real value to anyone who is looking for reasons to set up a repository and practical experience and lessons learnt on how best to do it. I will also provide a few example scripts of how it can be used and real-world examples of when it has proved useful.

Whilst I am not suggesting that my talk is a must see, I do think it offers good food for thought as to what might be achievable in mining AWR data. I am also hoping that audience feedback will generate other ideas.

More importantly, in my opinion, the day offers some good speakers and excellent talks, or maybe the other way around and should be attended if you possibly can. I think the UKOUG have a try before you buy offer but you need to confirm that from their website

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UKOUG Database SIG Leeds- review

Posted by John Hallas on May 14, 2013

Last week we held the UKOUG Database SIG in Leeds as I described in a recent post. It was a well attended event in a  central location with excellent refreshments available. – Thank you to UKOUG’s  Anna Crellin for organising the day so well.

The talks were all very good and I think the event was enjoyed by all. Neil Johnson wrote a blog entry about his experience of the day and of presenting for the first time. He has now got the bit between his teeth and wants to present a 2 hour masterclass at the December conference in Manchester – (perhaps I am exaggerating slightly)

I ran the ‘BitsandPieces’ session where audience participation was the key idea and this was achieved. The theme was small pieces of Oracle functionality that are not well known or used.

We discussed :-

The dbms_workload_repository.add_colored_sql procedure which allows you to capture specific pices of sql that individually would not appear as a top resource in AWR data. Using the package to add a sql_id and the data does then appear and performance can be fully explored. A good introductory  blog entry is available from Dion Cho at

  • The benefits of using restore points and  flashback database  were covered. Examples were given of flashing back through a 10g to 11g upgrade (if you might want to), using a restore point before making a major table or code change that might need to be rolled back (better than rolling forward from a previous backup) and using the same restore point repeatedly as part of performance testing. The point was made that anything that might include an OS command (such as dropping or resizing a datafile probably would not be recovered through so be careful with the command. My advice is that I consider it as the belt that goes with the braces of a full backup.
  • Invisible indexes – how easy they were to use and how they allowed the data_dictionary to be aware of the index but the optimizer ignores it. There was also a initialization parameter OPTIMIZER_USE_INVISIBLE_INDEXES  that allows the index to become visible at both a session and system level to allow full testing. Beware that if you rebuild an index it then becomes visible again.
  • One tip that came out was that in pre-packaged environments such as EBS when an index is not wanted, rather than drop it, mark it as invisible. Then when any upgrades or patches are applied the  index still exists in the dictionary and is not recreated as it might be if it had been dropped.
  • Another idea was the use of the opatch auto command. This came out in 11GR2 but not until PSU2. It manages a full GI and RDBMS patchset application and can stop all dependant databases, stop crs resources, stop crs, patch and restart everything. It can save a serious amount of time and is well worth investigating.

I did pick up another few interesting thoughts which I want to do a bit of research on and I will blog about those shortly.

So overall it  as a good day with a lot of community interaction, networking and a good laugh afterwards when about 15 of us went for a few beers.

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UKOUG Database Server SIG – Leeds May 9th

Posted by John Hallas on April 25, 2013

This is just a reminder for what I think is a strong Core DBA centric agenda being organised by the UKOUG

The location is the Met Hotel in Leeds, right by the station and the last meeting in Leeds several years ago, was well attended so I am sure this one will be as well.

The agenda is below


UKOUG Database Server SIG Meeting

Date: Thursday 9th May 2013

Time: 09:00 – 17:00

Location: Leeds/ West Yorkshire

Venue: The Met, Leeds



Registration and coffee




Welcome & Introduction

John Hallas, SIG Committee



Partition, Archive, Compress, Purge-Keeping your OLTP system on the road

David Kurtz, Go-Faster



Bits ‘n’ pieces

John Hallas, Wm Morrison Supermarkets Plc



Coffee & networking




Oracle support Update

Owen Ireland, Oracle



ZFS and NetApp provisioning for Oracle Databases

Mike Carew, Oracle







The Minimal Downtime PSU patching: proof of concept

Edgars Rudans, TSYS International



Coffee & networking




Contentious Small Tables

Neil Johnson, Osumo Ltd



AOB & Close





Posted in UKOUG | Tagged: , | 2 Comments »