Posted by John Hallas on December 9, 2013
As of 27th August 2013, 184.108.40.206, the final release of 11GR2 was made available – a new features document is available . I will give a quick bullet list of the new features and then discuss one very important one that is not mentioned.
- Oracle Data Redaction – provides a new ASO (cost £££) option to redact specified information, even at runtime, from within the database
- Trace File Analyzer and Collector, is a diagnostic collection utility to simplify diagnostic data collection on Oracle Clusterware, Oracle Grid Infrastructure – looks well worth investigating
- RACcheck – The Oracle RAC Configuration Audit Tool – to perform regular health checks as well as pre- and post-upgrade best practices assessments. Only written for linux so needed adapting for HPUX and needs to have the root password – an issue for many DBAs
- Database Replay Support for Database Consolidation – run lots of scenarios- batch, online, monthly process all at the same time even though captured at different periods.
- Optimization for Flashback Data Archive History Tables – use the OPTIMIZE DATA clause when creating or altering a flashback data archive.
So the one that has not appeared in that list, probably because it is not a new feature as such is tan additional value for the init.ora parameter OPTIMIZER_DYNAMIC_SAMPLING. This comes into play when a table does not have any statistics and the parameter is enabled. The previous default setting of 2 was to use dynamic statistics if at least one table in the statement has no statistics and the number of blocks that the statistics would be based on would be 64 and the value could range between 2 and 10 , each value doubling the number of blocks that will be sampled. The new value of 11 means that the optimizer will gather dynamic statistics automatically whenever the optimizer deems it necessary and based on the number of blocks it thinks appropriate.
My testing has shown a couple of anomalies between the two versions it exists on ( 220.127.116.11, 18.104.22.168). Read the rest of this entry »
Posted in 11g new features, 12c new features, Oracle | Tagged: 22.214.171.124 new features, 126.96.36.199, dynamic sampling, OPTIMIZER_DYNAMIC_SAMPLING., optimizer_dynamic_sampling=11, RACcheck, Trace File Analyzer and Collector | Leave a Comment »
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: AWR repository, National Football Museum, Tech 13, ukoug conference | 2 Comments »
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: tech13, UKOUG Manchester | 2 Comments »
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 188.8.131.52 – 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: recover table sysbackup role, Tech 13 conference, UKOUG | Leave a Comment »
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 »
Posted by John Hallas on November 18, 2013
Today I had the opportunity to see Amazon Web Services being used in a real environment and I was very impressed with what I saw. The ability to drive any configuration you want from a menu system and pay for only what you use seems to be the way that computing must go.
It must be a boon for small software houses who cannot afford lots of kit and expensive DBA and Linux resource to configure the systems. You just logon and select the database version of choice, whether it will run on Windows or Linux (many variants seem to be available) and away you go – in a few minutes you have a full server deployed and ready to use.
Conversely, I am used to working at Blue chip companies who have made a very expensive commitment in infrastructure and have enterprise license agreements in place. It would be quite hard to justify additional spend when you have a lot of kit sitting around – even though typically it might take a few days for a new OS to be installed, database software installed and databases built and configured.
To someone new to cloud computing, the hosting of key business systems and more importantly the data on those servers must be seen as the major risk and deterrent to putting production systems out in the ether and I am sure a high percentage of externally hosted systems are non-production just for that reason.
AWS have a nice 10 minute video on setting up a web-hosted application which is well worth a view. Looking around on the net there are many more links and user cases available and of course Amazon are not the only suppliers. Oracle have a 2 minute segment which, whilst delivered by a salesman type with amazing title of VP – Customer Experience Strategy gives some of the benefits and does advocate a hybrid style of computing, some held locally and some held in the cloud.
I am sure I will return to this subject again, probably in more detail as I investigate further. In the meantime I can continue to configure and patch my Linux build on my laptop or I can try a free (for 1 year) micro-site on AWS. Seems a bit of a no-brainer to me.
Posted in Oracle | Tagged: Amazon Web Services, AWS, Iaas, Paas, Saas | Leave a Comment »
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.
Posted in Oracle, UKOUG | Tagged: AWR repository, saving OEM data, tech13, ukoug conference | Leave a Comment »
Posted by John Hallas on October 21, 2013
When I read the list of 12c new features the one that interested me immediately was the ability to be able to recover a table from an RMAN backup. This seemed to be quite challenging as RMAN is an image copy of blocks and a table is normally copied using a logical Datapump export.
What Oracle have delivered is a packaged technique which recovers only the necessary tables so as to get the data dictionary and any undo/redo segments necessary to get all the data back to a specific point in time whether that be a SCN or a timestamp.
The whole process is very neat and it creates a new database, recovers the necessary datafiles and then creates a dumpfile of the necessary table, puts the data back to wherever you want and then deletes all evidence and traces of what it has done.
I have provided a full example of such a recovery below and it is well worth looking at to see how it all works.
A few things seem worthy of note and even further investigation. Read the rest of this entry »
Posted in 12c new features, Oracle | Tagged: 12c, 12c new features, recover table, RMAN | 2 Comments »
Posted by John Hallas on October 10, 2013
With a subtitle of ‘The 10 commandments of being a good DBA within a DBA team”
I have been considering for a while what might make a good DBA manager and how that has a knock-on effect of developing DBAs and giving them an insight into best practises. These are some of my thoughts. I am not pretending to be a good manager, but I do try my best and these are some of the methods which I think have merit.
They are in ascending order of importance, however my top two wrote themselves, if you interview a DBA and ask him what the job is about and he does not come up with these two then I would be tempted to give up straight away. Read the rest of this entry »
Posted in Oracle, Uncategorized | Tagged: being a good DBA, dba best practises, dba manager, dba team management, how to be a DBA | 1 Comment »
Posted by John Hallas on October 3, 2013
This post was forwarded to me by Vitaly Kaminsky who did work with me but has now bettered himself elsewhere. He writes :-
I have recently been involved with performance tuning of a database layer for the major Dutch website which was preparing for the “crazy days” of sales on the 2nd to 5th of October.
The general setup was as follows:
2-node physical RAC cluster with fast storage layer running ORACLE 11gR2 SE and ASM.
The important bit above is the “SE” which stands for Standard Edition and implies no performance packs, no AWR, no SQL tuning and no partitioning.
The shop application makes heavy use of Oracle Text functionality and the purpose of the tuning was to ensure we can get 12000 orders per hour through the system. Each of the orders would create a single insert and numerous updates of a CLOB in XML format. This is actually the total info we managed to get from the vendor on what the application performance tuning should be focused on.
As expected, after the first test runs, it became apparent that the stumbling block was literally a block of CLOB storage. When there was enough padding space, the application ran fine and then, suddenly, the database would grind to a halt with “enq: HW – contention” waits. Read the rest of this entry »
Posted in 11g new features, Oracle | Tagged: Bug 6376915, clob, lob storage, VENT='44951', x$ksqst | Leave a Comment »