Sunday, July 19, 2015

E4 2015 it is a wrap

Long overdue but I had a very busy month of june and july sofar.

 This year I was invited at E4 as a speaker. This was my second time in the USA and
 I really enjoyed every bit of it, a great conference , great people nice interactions unsurpassed hospitality. Andy Colvin and his wife Kate came to pick me up at the airport, the belt where I had to get my luggage was very appropriate.

Once the luggage was there it was the turn of Martin Bach to get picked up at the airport he landed at about the same time at another terminal.
Andy together with the amazing Veronica arranged a great Mexican Restaurant for us that night it was delicious and we finished the evening in a great beer pub in Southlake .

The great thing about E4 is that it is completely focussed on engineered systems and how they work, the other great thing is that there is one track which makes you attend plenty of interesting session you might miss otherwise.

 I really enjoyed it and learned a lots of engineered systems I didn't even know before such as the VCA, Virtual Compute Appliance, James Anthony really nailed this presentation it was very interesting and well presented.

 Other highlights for me were :

  •  Tanel Poder & Kerry Osborne's keynote about the hybrid world, Conventional RDBMS and the NOSQL movement will continue to coexist together and are complimentary 

  • Tyler Muth about Super Cluster and in-memory very interesting since I didn't have not a lot of exposure of ORACLE 12c so far 

  •  Roger MacNicol What’s new in Exadata Smart Scan and which was the version we just upgraded to, so this was a great refresher

  •  Sue Lee "Tips and Tricks for Successful Consolidation on Exadata" I had a lot of eye openers there and got really good info about resource manager and IORM. Some interesting new things in Storage Cell version such as Flash Cache Min and Flash Cache Limit are available now. 

  •  Martin Bach's talk about HCC Compression, I saw this one already a couple of times and it is really a presentation like wine, it gets better and and better, I you are able to attend this talk at some other conference please do so it is really very world while and Martin knows his stuff and has very good presentation skills.

  •  Frits Hoogland, in Frits' own style he did a superb presentation about memory SGA the differences in allocation between AMM and ASMM and manual, PGA how it allocated, etc very interesting but have to go through the presentation again to grasp everything 

  • Kodi's Umamageswaran session he pointed out what is in store on the technology level: Networking 40Gbps Ethernet, 100Gbps infiniband Persistent memory etc. 

  •  Mauro Pagano's session about health checks was really incredible what a horror story very entertaining, if ever a book should be written about worst practices this use case is a good candidate.

 My talk was about the Sparc Super Cluster "Super Cluster: the SWISS army knife of the Engineered Systems", I had the first slot on Tuesday and had about 100 people in my session,

I was bit nervous since a lot of my hero's were in the room and also the product manager of Super Cluster Michael Palmeter and Tyler Muth Super Cluster affiando.

The talk went ok and I did get good feedback and enjoyed it a lot.

 The conference is one thing but being able to talk offline with people like Karl Arao, Tanel Põder, Kerry Osborne, Mauro Pagana, Cary Millsap, Carlos Sierra, Andy Colvin, Tyler Muth, Michael Palmeter, Frits Hoogland, Martin Bach, Tarmo Alasoo, Radu Parvu, Jason Arneil, Hank   and all the passionate attendees just feels great and that is what attending this conference

I really enjoyed this conference a lot and got to know some nice people, thank you Veronica , Chanea and all the others of the organisation, you really made us speakers feel like kings.

A big thank you to Andy and Kate,  thanks for you warm welcome and even warmer hospitality really appreciated.

Next year there will be a European E4 as well in April, just a couple hours of flight for most of the Europeans, so you have no excuse to not attend this great engineered systems conference. check enkitecs website for more info

and yes it is true everything is bigger in Texas :-)

adding storage cells : appliance mode

Due to capacity issues 2 extra storage cells had to be added to the already 3 licensed high performance X3 cells on the Super Cluster T4. Some details about the installation Cellsrv GI DB The process was quite straight forwards and is documented here in summary : create cell disks create grid disks on them exactly the same as on the existing cells with the same offsets for each disk group here an example of the first disk group on our cells
         DATA_DG_CD_00_celadm01   423G    active  ONLINE  Yes     32M
         DATA_DG_CD_01_celadm01   423G    active  ONLINE  Yes     32M
         DATA_DG_CD_02_celadm01   423G    active  ONLINE  Yes     32M
         DATA_DG_CD_03_celadm01   423G    active  ONLINE  Yes     32M
         DATA_DG_CD_04_celadm01   423G    active  ONLINE  Yes     32M
         DATA_DG_CD_05_celadm01   423G    active  ONLINE  Yes     32M
         DATA_DG_CD_06_celadm01   423G    active  ONLINE  Yes     32M
         DATA_DG_CD_07_celadm01   423G    active  ONLINE  Yes     32M
         DATA_DG_CD_08_celadm01   423G    active  ONLINE  Yes     32M
         DATA_DG_CD_09_celadm01   423G    active  ONLINE  Yes     32M
         DATA_DG_CD_10_celadm01   423G    active  ONLINE  Yes     32M
         DATA_DG_CD_11_celadm01   423G    active  ONLINE  Yes     32M
ok we did that that way the configuration was exactly the same on the cells. on the database node we added the ip's of the newly added cells. I was a bit confused by the fact that nothing needed to be added on the storage cells because I recalled that there was a functionality introduced in one of the more recent storage cell versions that made them "talk" to each other on rebalance operations. But adding the ip's in cellip.ora on the db node was enough and then we were ready to rebalance the disk group
DISK 'o/*' 
DISK 'o/*' 
rebalance power 32 
and kaboum
ERROR at line 1: 
ORA-00600: internal error code, arguments: [kfgpCreate_60], [12], [0], [65535], 
[65535], [65535], [65535], [], [], [], [], []
luckily asm was still running but being already pretty late after a day of migrations this was not funny at all. after chatting with support they suggested to disable appliance.mode on the disk group
after we did that the addition of the disks worked
DISK 'o/*' 
DISK 'o/*' 
rebalance power 32 

Diskgroup altered. 
When the rebalance was finished we put appliance.mode again to TRUE
more info can be found in note EXADATA : What Is Oracle ASM appliance.mode Attribute (Doc ID 1664261.1) So it looks like the appliance.mode is an optimisation I wonder if it is the fact that cells can communicate directly instead of using the host for rebalance operations, however that is not literally stated in the metalink note. hope this helps if you encounter this

Monday, May 4, 2015

upgrading to GI

Some weeks ago I patched the GI from to I implemented the fix for the listener poisoning issue you can read about it here here is the original listener.ora

here the upgraded one
REGISTRATION_INVITED_NODES_LISTENER_SCAN2=()            # line added by Agent
REGISTRATION_INVITED_NODES_LISTENER_SCAN1=()            # line added by Agent
REGISTRATION_INVITED_NODES_LISTENER_SCAN3=()            # line added by Agent
ENABLE_GLOBAL_DYNAMIC_ENDPOINT_MGMTLSNR=ON              # line added by Agent

The installer / upgrade process removes these entries, I saw similar behaviour with the dbca when you have IFILES in the tnsnames.ora, most annoying these entries get removed .... NOTE : I anNonimized the ip addresses

Sunday, April 19, 2015

OLTP compression and Updates

I did some small tests (actually more troubleshooting ) with OLTP compression, a couple of weeks back.

Some execution times nearly doubled, I wanted to get a clear understanding of what happened so I asked to trace the procedure.

Which was easy since dbms_application.set_module could be used in the procedure to set the module and the action.

This made it much less cumbersome to enable the trace, the  dbms_monitor package has a procedure which allows you to start tracing whenever the combination of service_name and module is used very handy

so in the end I used this to trace


That made it easy to trace as soon as the procedure was launched and avoid to play around with logon triggers and trace more, then necessary.

I did the tests both with a warmed up DB cache as with a flushed db cache and will do them again next week the results were in the same league

But back to the problem, speed of the query was much slower.

I checked both


45810 rows updated.
Elapsed: 00:00:01.59


45810 rows updated.
Elapsed: 00:00:04.38

Quite a difference ...

The query looks a bit like this I had to obfuscate because of privacy reasons :


(COLUMNS ....)





This is how the trace file looks like after being processed with Method R profiler a tool i really can recommend, it save me lots of time, time you can use to solve you performance issue, instead of crawling through raw trace files ...

Here You see the uncompressed trace

here is the compress trace

Much more blocks in Current mode

In both cases the last step of the execution plan takes quite a bit

the last step of the compressed update took ; ~ 3,25 sec (4,37 -0,34 ....)
the last step of the non compressed update ;  ~ 0,77 sec

So unbelievable that I will redo some tests again next week and add them to the post.

Thursday, April 2, 2015

12c adr support

I noticed that with the upgrade of GI to 12c some new things are in the ADRCI
 the scan listeners are know under adrci control as well, 
In 12c,(


ADRCI: Release - Production on Tue Mar 31 18:17:21 2015

Copyright (c) 1982, 2014, Oracle and/or its affiliates.  All rights reserved.

ADR base = "/u01/app/grid"
adrci> show control
DIA-48448: This command does not support multiple ADR homes

adrci> show homes
ADR Homes:
adrci> set home diag/tnslsnr/node2/listener

on 11g this was not the case

while on 11204 …

ADRCI: Release - Production on Tue Mar 31 18:21:18 2015

Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.

ADR base = "/u01/app/grid"
adrci> show homes
ADR Homes:

Tuesday, March 31, 2015

assumption is the mother of ....

We had complaint about a batch job that took much longer to complete on environment A then on environment B.

I checked and indeed the plans where different

As we recently updated from BP12 to BP15 on that environment (A) my first idea was that this caused the issue,  to exclude everything I imported the table stats from the working environment B to the environment A.
Still I got the same plan.

I checked the system stats they were the same.
I used Mauro Pagano's excellent SQLd360 tool get it here and couldn't see anything (that's ENTIRELY my fault I could really work on this and was multitasking a lot due to other constraints;-).

I ran a 10053 optimizer trace and saw that there were fix controls not used on env B and only FTS were used in SINGLE TABLE ACCESS PATH , .... bizar 

Environment A

  Single Table Cardinality Estimation for TABLE_X[TABLE_X
  Column (#2): 
    NewDensity:0.000210, OldDensity:0.000476 BktCnt:254, PopBktCnt:2, PopValCnt:1, NDV:4725
  Column (#2): COL2(
    AvgLen: 7 NDV: 4725 Nulls: 0 Density: 0.000210 Min: 113898 Max: 814396873
    Histogram: HtBal  #Bkts: 254  UncompBkts: 254  EndPtVals: 254
  Column (#3): 
    NewDensity:0.000019, OldDensity:0.001339 BktCnt:254, PopBktCnt:18, PopValCnt:9, NDV:48180
  Column (#3): COL3(
    AvgLen: 7 NDV: 48180 Nulls: 0 Density: 0.000019 Min: 113328 Max: 816880773
    Histogram: HtBal  #Bkts: 254  UncompBkts: 254  EndPtVals: 246

  Table: TABLE_X  Alias: TABLE_X
    Card: Original: 633107.000000  Rounded: 1  Computed: 0.00  Non Adjusted: 0.00
  Access Path: TableScan
    Cost:  1113.98  Resp: 1113.98  Degree: 0
      Cost_io: 1100.00  Cost_cpu: 180830851
      Resp_io: 1100.00  Resp_cpu: 180830851
  Best:: AccessPath: TableScan
         Cost: 1113.98  Degree: 1  Resp: 1113.98  Card: 0.00  Bytes: 0

While on the other env B

  Single Table Cardinality Estimation for TABLE_X[TABLE_X
  Column (#2): 
    NewDensity:0.000210, OldDensity:0.000476 BktCnt:254, PopBktCnt:2, PopValCnt:1, NDV:4725
  Column (#2): COL2(
    AvgLen: 7 NDV: 4725 Nulls: 0 Density: 0.000210 Min: 113898 Max: 814396873
    Histogram: HtBal  #Bkts: 254  UncompBkts: 254  EndPtVals: 254
  Column (#3): 
    NewDensity:0.000019, OldDensity:0.001339 BktCnt:254, PopBktCnt:18, PopValCnt:9, NDV:48180
  Column (#3): COL3(
    AvgLen: 7 NDV: 48180 Nulls: 0 Density: 0.000019 Min: 113328 Max: 816880773
    Histogram: HtBal  #Bkts: 254  UncompBkts: 254  EndPtVals: 246
  ColGroup (#1, Index) IX_4
    Col#: 4 5    CorStregth: -1.00
  ColGroup Usage:: PredCnt: 2  Matches Full:  Partial: 
  Table: TABLE_X  Alias: TABLE_X
    Card: Original: 633107.000000  Rounded: 1  Computed: 0.00  Non Adjusted: 0.00
  Access Path: TableScan
    Cost:  1113.55  Resp: 1113.55  Degree: 0
      Cost_io: 1100.00  Cost_cpu: 180830851
      Resp_io: 1100.00  Resp_cpu: 180830851
  Access Path: index (AllEqRange)
    Index: IX_2
    resc_io: 9.00  resc_cpu: 69774
    ix_sel: 0.000019  ix_sel_with_filters: 0.000019 
    Cost: 9.01  Resp: 9.01  Degree: 1
  Access Path: index (AllEqRange)
    Index: IX_3
    resc_io: 28.00  resc_cpu: 257919
    ix_sel: 0.000210  ix_sel_with_filters: 0.000210 
    Cost: 28.02  Resp: 28.02  Degree: 1
  ****** trying bitmap/domain indexes ******
  Access Path: index (AllEqRange)
    Index: IX_2
    resc_io: 3.00  resc_cpu: 23964
    ix_sel: 0.000019  ix_sel_with_filters: 0.000019 
    Cost: 3.00  Resp: 3.00  Degree: 0
  Access Path: index (AllEqRange)
    Index: IX_3
    resc_io: 3.00  resc_cpu: 47964
    ix_sel: 0.000210  ix_sel_with_filters: 0.000210 
    Cost: 3.00  Resp: 3.00  Degree: 0
  Bitmap nodes:
    Used IX_2
      Cost = 3.001919, sel = 0.000019
    Used IX_3j
      Cost = 3.004938, sel = 0.000210
  Access path: Bitmap index - accepted
    Cost: 6.007407 Cost_io: 6.000536 Cost_cpu: 91721.496173 Sel: 0.000000
    Not Believed to be index-only
  ****** finished trying bitmap/domain indexes ******
******** Begin index join costing ********
  Access Path: index (FullScan)
    Index: IX_1
    resc_io: 1439.00  resc_cpu: 136869152
    ix_sel: 1.000000  ix_sel_with_filters: 1.000000 
    Cost: 1449.25  Resp: 1449.25  Degree: 0

Being in a hurry because I was busy with plenty of stuff  I assumed  that fix_control was the problem

however setting fix_control didn't change a thing so I went back to check  the trace with a colleague  and then we saw following

Table Stats::
  Table: TABLE_X  Alias: TABLE_X
    #Rows: 633107  #Blks:  4056  AvgRowLen:  43.00  ChainCnt:  0.00
Index Stats::
  Index: IX_1  Col#: 1
    LVLS: 2  #LB: 1437  #DK: 633107  LB/K: 1.00  DB/K: 1.00  CLUF: 37633.00
  Index: IX_2  Col#: 3
    LVLS: 2  #LB: 1665  #DK: 48180  LB/K: 1.00  DB/K: 5.00  CLUF: 287723.00
  Index: IX_3  Col#: 2
    LVLS: 2  #LB: 2103  #DK: 4725  LB/K: 1.00  DB/K: 25.00  CLUF: 118278.00
  Index: IX_4  Col#: 4 5
    LVLS: 2  #LB: 2490  #DK: 14906  LB/K: 1.00  DB/K: 2.00  CLUF: 36217.00

We checked the status of the indexes they were INVISIBLE, when they were put back to VISIBLE the correct plan was choosen again ...

Moral of the story : As one of my previous managers (probably the best I had so far but that is another story )said Assumption is the mother of all f*ck ups, don't think that everything is a complicated problem and check basic things, and take your time to check things don't do 50 things at the same time, man anyway can't multitask ;-------------)
luckily in the end it didn't take to much time to identify the issue...

Thanks @MartinDBA, @Mautro and everyone interacting in the discussion on twitter

Saturday, March 14, 2015

wow what a seminar

wow it’s behind us again a great OUGN Varseminar 2015,big shout out to the boa(r)(t)d  to have made this again a success. 

You’ve set the bar very high for coming years, I hope to be able to be part of other future editions  ! 
It was a very good idea to put the exhibition hall not on the same floor as the talks,giving more breathing room around the rooms

Apart from the fact that a seminar on a boat creates a special bond with the people aboard the quality of the talks was really very good, i learned plenty of things...

I really enjoyed being on a boat with people passionate about there job in fact for most of the people it more then just being a job it is a passion , vocation ,...

It was great to meetup with old friends and make new ones

my personal highlights not in any particular order

were the sessions of :

Neil Johnson (@neiljdba) about contentious small tables really a very good presentation I learned a lot about the hakan factor, I strongly recommend to go to follow this session on other conferences this year, beside that Neil is a great guy to hangout with. Unfortunately I missed his talk about jumbo frames...but the good news I found his slides already ;)

Kellyn Potvin-Gorman  also known as @DBAKevlar talking about AWR Warehouse thanks to her presentation I finally know that this is a “free” limited license if you have licensed tuning and diagnostic pack for your  databases, I will start pushing for it at my current customer,because it can really save you bacon and lots of discussio. Her talk about EM 12c was also great by the way despite that she was pretty i'll suffering from her sinusses, so really well done

Jan Karremans’ session ‘ok now my database crashed’ was a very good reminder on how important it is to take this part of your oracle installation not too lightly, btw Jan is pretty (hyper) active on twitter ;-) here (@johnnyq72)

James Morle’s (@JamesMorle) session about opitmizing table scanning  and how to tune all layers of the cake even the blue ones

Luis Marques (@drune) session about Rat was of a very high quality so was his talk about Resource Manager, this is a subject that needs bigger attention especially in the actual spirit of consolidation

I really enjoyed the ‘Instructor’ aka Uwe Hesse’s presentations about the broker and fra I envy his courage of doing a complete talk with live demo’s. (@UweHesse)

I had a blast doing the SE Round Table BE (boat edition) with SE lady Ann Sjokvist (@annsjokvist) and my good friend Jan Karremans, I liked the chemistry that was going on on stage.
SE edition can be a good solution for you, it depends on your business needs and it is an easy step up to EE when you later would need those features. Each of us three looked the product from a Different angle 
Ann really has lots of experience with it and is a really advocate, Jan Looked at it from the business side, and I for my part I am a spoiled EE dba who realises that you need to do correct size matching and see if the 

I had my own talk about a great underestimated product in the engineered systems line up the Sparc Super Cluster, I’ve been working with this product since beginning 2014 and it is for me very much the Swiss Army knife of the engineered exadata systems, providing an un-paralleled versatility and flexibility. 
I liked the questions and discussion with Jacco Landlust that came offline after my talk about Super Cluster.

I would like to explicitely thank Oyvind Isene (@OyvindIsene) and Kjell Tore for many of us international speakers you guys are the public face of OUGN. Speaking For myself if I wouldn’t have come to OUGN as a delegate in 2013 after talking to Oyvind at #OOW2012  I wouldn’t be speaking now, so Oyvind  I owe you  a lot. I hope the next board will continue your work and the investments of blood sweat and tears you two did.

I would also like to thank portrix Florian , Connie and Bjoern (@brost)for the great gin / buffet you organised in Kiel. It becomes clearly a tradition.

Too bad I missed several sessions I due to overlap ;-(

Nice meeting you all girls and guys

Thank you 

Jan Karremans
Heli Helskyaho ;-)
Debra Lilley
Brendan Tierney
Oyvind Isene
Kjell Tore
Frits Hoogland
Christian Antognini
Neil Johnson
Kellyn & Tim Gorman
Gurcan Orhan
Bjoern Roest Florian 
Andy Colvin & wife
James Morle
Luis Marquis
Kelly Potvin
Tim Gorman
Jacco Landlust
Alex Nuijten
Patrick Barrel
Magnus Fagertun
Mark Rittman
Eric Van Roon

Thank you all for making my OUGN 15 so great

If you haven't decided yet maybe this small video and some pictures (sorry I am not so good with an iphone DSLR user) can persuade you to attend or submit for OUGN16