On Monday we had some performance problems on a system that includes a database which uses shared servers. The top wait was “virtual circuit wait”. Here are the top 5 events for a 52 minute time frame:
Top 5 Timed Foreground Events
||Avg wait (ms)
||% DB time
|virtual circuit wait
|db file sequential read
In my recent post I showed how log file sync (LFS) and log file parallel write (LFPW) look for normal systems. I think it would also be interesting to compare that to the situation when LGWR does not have enough CPU.
I happen to have collected LGWR and database-level trace files for a 18.104.22.168 database on a Solaris 10 server which was under serious pressure (50 threads mostly inserting and committing data, only 32 (more...)
I’m proud to be one of the Oracle ACE Directors. Watch the video for some viewpoints on the Oracle ACE program from both Oracle and other Oracle ACEs.
There is a very common mistake in troubleshooting log file sync (LFS) waits: comparing its average time to average log file parallel write (LFPW) and trying to deduce from that whether the root cause of the wait is slow I/O or something else. The fact that this approach is recommended by Oracle itself (e.g. MOS 1376916.1) and many independent experts unfortunately doesn’t make it any less wrong.
It is well known that averages and ratios can distort the reality (Milsap and (more...)
I’ll be in Openworld again this year, and have a couple of speaking slots…
I’ll talk about new features for developers in 12c on Sunday, Sep 28, 2:30 Moscone South 303
and of course, at the awesome Oaktable world..
Drop in, learn some cool things, or just pop up and say Hello!
Just got the invitation to the first AZORA (Arizona Oracle user group) meeting on October 23. Here is the link: url
It’s 2 pm at Oracle’s office, 2355 E Camelback Rd Ste 950, Phoenix, AZ.
I’m looking forward to it!
Catchy title, don’t you think? My session has been moved to Monday 4 P.M., in direct conflict with Tom Kyte – and Keith Laker, who asked me to present in the first place. Avoid the lines: come see the MATCH_RECOGNIZE clause push great pre-12c solutions into retirement. As a bonus, be the first person on your block able […]
Overview only :
Complete prerequisites on target server see my step by step document
Step 2 :
run adpreclone procedure on database tier and application tier
Step 3 :
copy db, apps, inst to target machine and also change ownership
db — database user
apps,inst — appl user
Step 4 :
take rman backup and copy to target machine
Restore database to target machine using rman
change database name
Zone Maps are new index-like structures that enables the “pruning” of disk blocks during accesses of the table by storing the min and max values of selected columns for each “zone” of a table. A zone is simply a range of contiguous blocks within a table. Zone Maps are similar in concept to Exadata storage […]
Not all documentation is created equal. Too much time is spent on formal design documents that are immediately outdated, and too little is spent on writing code comments.
Make sure your process requires and rewards good code comments. And make sure your architecture diagrams are kept up-to-date.
This illustration is from my weekly “Technology That Fits” newsletter – sign up here.
When i try integrate EBS and Siebel, its getting below error in siebel
Error invoking service ‘XXACE_CREATE_RECEIPTS_SIEBEL_PortType_2′, method ‘XXACE_RECEIPTS’ at step ‘Transport’.(SBL-BPR-00162)
Operation ‘XXACE_RECEIPTS’ of Web Service ‘http://xmlns.oracle.com/apps/ar/soaprovider/plsql/xxace_create_receipts_siebel/.XXACE_CREATE_RECEIPTS_SIEBEL_Service’ at port ‘XXACE_CREATE_RECEIPTS_SIEBEL_Port’ failed with the following explanation: “User not authorized to execute service.”.(SBL-EAI-04308):
Go to EBS Integrated SOA –> Choose particular interface (Interface type — plsql — Receivable )
revoke sysadmin privilege and then (more...)
Based on my article in the latest issue of OTech Magazine, I am offering a free teleseminar (by phone or Skype) on how to live a happy, meaningful life in IT.
Programmers have a head start over the rest of humanity in leading happy, meaningful lives. If you have not yet reached complete enlightenment, I encourage you to sign up and invest 30 minutes listening to this call. It might improve your life.
I wanted to expand on a thread in a LinkedIn group I’m part of, where one of the members wrote “It’s funny when 2 experts are arguing about who is better”, using Tom Kyte and Jonathan Lewis as examples of people they say are “Experts”.
Disclaimer: I have not spoken to Jonathan or Tom in regard to their viewpoints on this subject, so this shouldn’t be taken as them saying any of this, just my (more...)
The summer edition of OTech magazine has just been published – 111 pages packed with information from international Oracle technology experts.
Authors and topics are:
- Sten Vesterli – The Spiritual Programmer
- Scott Weseley – APEX 5.0 New Features
- Patrick Barel – Dear Patrick
- Emma Groomes & Crystal Walton – KScope 2014
- Anar Godjaev – How to protect your sensitive data using Oracle Data Vault
- Debra Lilley – Women in IT Initiative
- Lonneke Dikmans – (more...)
While 8k is the default block size, Oracle supports other block sizes, too. Smaller block sizes (more commonly, 4k) are encouraged for OLTP workloads to reduce concurrency, and even smaller block size, 2k, is recommended for databases running on “Advanced format” (or “4K”) storage. Oracle documentation warns us of possible implications when storing larger rows in 2k/4k blocks, such as potentially larger space overhead due to metadata, or even possibility of row chaining. What it (more...)
Gartner has just released another iteration of their classic “Hype Cycles.” They are up to more than 100 different topics now, but one interesting graph is one is the one for Emerging Technologies.
Source: Gartner Hype Cycle for Emerging Technologies 2014
I want to comment on a couple of points from this graph:
- Internet of Things as peaking – completely agree. Everybody is talking about it but what do we have? An internet-connected smoke alarm.
- Big (more...)
Anyone who has used Oracle for a while will be familiar with the Parent/Child locking "issue" when it comes to tables and indexes on foreign keys. For many years you’d hear people crying "bug" etc but thankfully most now know the reason, and accept it as sensible behaviour.
But lets take a look at a slight variation on that theme.
Lets start with a table called "LOC" which will be our parent table in (more...)
I’m not in favour of calling books a “must-read”, but if you want to get your own book commercially published, I have to say you must read Write the Perfect Book Proposal: 10 That Sold and Why, 2nd Edition.
The main force of this book is that it explains the publishing industry from the inside: What a publisher is looking for. The authors honestly explain what the publisher will and will not do, and that (more...)