New in Java 8 : Default and static methods in interfaces

Default method’s  (aka Defender methods) in interfaces are new in Java 8. They enable you to define a default implementation of a method in the interface itself.

If an interface is implemented by several classes, it’s hard to add method’s afterwards, as it will break the code and require all implementing classes to define the method as well. Adding a method to the interface, and defining a default implementation for it, will resolve this problem.

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Patch applied or not in R12

you can get the patch applied details in EBS R12 from below command

 

select AP.PATCH_NAME, AP.PATCH_TYPE, AD.DRIVER_FILE_NAME, AD.CREATION_DATE, AD.PLATFORM,AL.LANGUAGE
from AD_APPLIED_PATCHES AP, AD_PATCH_DRIVERS AD, AD_PATCH_DRIVER_LANGS AL
where AP.APPLIED_PATCH_ID = AD.APPLIED_PATCH_ID
and AD.PATCH_DRIVER_ID = AL.PATCH_DRIVER_ID and AP.PATCH_NAME='17627621'

Compile pll file in R12

If you like to compile pll file in R12, you can use frmcmp_batch command instead of using  f60gen

 

Example :

cd $AU_TOP/resource

frmcmp_batch module=/u02/backup/appltrng/apps/apps_st/appl/au/12.0.0/resource/HRLOCAL.pll userid=apps/apps output_file=/u02/backup/appltrng/apps/apps_st/appl/au/12.0.0/resource/HRLOCAL.plx module_type=library batch=yes compile_all=special


Theory of Constraints: the rise of NoSQL

 

nosql

http://martinfowler.com/bliki/NoDBA.html

Why did NoSQL arise?  The rise of NoSQL makes no sense if you read an article like “Why You Should Never Use MongoDB”  and the ycombinator replies . The I read something like this “Why You Should Use MongoDB” and don’t find any reasons just  ranting about why the first article was shoddy.

One theory proposed by Martin Fowler is that NoSQL arose as a way to get (more...)

History of AMIS Blog design, Congratulations AMIS

It is July 2014 and the AMIS Blog celebrates it’s 10th anniversary. While diving in the history of the AMIS Blog it is very interesting (amusing and somewhat shocking) to see were we came from. Using the Internet Archive (https://archive.org) I made some screenshots of the AMIS blog depicting the different styles. We made 3 major steps in the design of the blog. Please join me for this trip through memory lane….

640*480 (more...)

Used Delphix to quickly recover ten production tables

Yesterday I used Delphix to quickly recover ten production tables that had accidentally been emptied over the weekend.  We knew that at a certain time on Saturday the tables were fully populated and after that some batch processing wrecked them so we created a new virtual database which was a clone of production as of the date and time just before the problem occurred.  We could have accomplished the same task using RMAN (more...)

Debugging Faulty Assumptions

I wanted to install Oracle JDevelper 12.1.3 – a version that I had been eagerly awaiting. Since my primary machine is a MacBook, I wanted to install it on OS X 10.9.3.

I downloaded the generic installer and found that the install didn’t run. Since OS X had disappeared from the documentation, I assumed that I would have to fiddle around until I found a combination of JDK and OS (more...)

No Hakan factor for IOT

Sadly there seems to be no concept of the Hakan factor for an IOT.

I have an application which merges into an IOT, the merge incrementally populating a swag of initially null columns, hence growing the rows in size.  Some simple benchmarking shows the overhead of this versus merging into a table with pre-populated values:

SQL> create table T1
  2   ( x int primary key,
  3     y1 number(10),
  4     y2 number(10),
  5     y3 number(10),
   (more...)

Comparisons

Catching up (still) from the Trivadis CBO days, here’s a little detail which had never crossed my mind before.


where   (col1, col2) < (const1, const2)

This isn’t a legal construct in Oracle SQL, even though it’s legal in other dialects of SQL. The logic is simple (allowing for the usual anomaly with NULL): the predicate should evaluate to true if (col1 < const1), or if (col1 = const1 and col2 < const2). The thought that (more...)

kksfbc child completion

I’ve run into the wait “kksfbc child completion” a few times over the past but found very little written about it. I don’t have an explanation, but I have something that might be as good – a way to reproduce it. By being able to reproduce I at least test theories about it.
I ran a tight loop of

insert into t value(1);
See anything strange? I put “value” instead of “values” so the (more...)

Redo log waits in Oracle

Redo

Redo is written to disk when
User commits
Log Buffer 1/3 full (_log_io_size)
Log Buffer fills 1M
Every 3 seconds
DBWR asks LGWR to flush redo
Sessions Committing wait for LGWR

Redo Log Wait Events

Log file Sync

 

Wait for redo flush upon:
Commit
Rollback
Arguments
P1 = buffer# in log buffer that needs to be flushed
P2 = not used
P3 = not used
Commit less
Often possible in loops that commit (more...)

Development Platform Disconnect

Each year at the annual Oracle ACE Director briefing, I look around at the laptops my fellow ACE Directors are carrying. More and more of them are MacBooks – I think we were up to around 50% last year.

That makes it all the more puzzling that the installation guide for the latest version of Oracle JDeveloper (12.1.3) does not mention OS X installs at all. The 12.1.2 version had sections (more...)

12c nasty with remote query optimization

We have a fairly common query process, where we run a MERGE command to compare a remote table to a local copy of it, as "poor mans" Golden Gate to bring that table up to date on a regular basis.  [Editors note: Writing MERGE's is more complicated but a lot cheaper than Golden Gate :-)]

After an upgrade to 12c, the performance of some of the MERGE’s went very bad…and you can see what (more...)

Testing…the surgeon’s approach

I played a lot of volleyball in a bygone life :-) and subsequently ruined my knees to the extent that I needed surgery. I got a shock when the surgeon (after a series of x-rays and checks) said to me: "Of course, we’ll only know once we’re in there".

So here’s a body part (a knee) that’s had hundreds of thousands of years to evolve, so you’d expect that knees are pretty much the same (more...)

Upgrade to 12c … credentials

We did a "real" upgrade to 12c this weekend, where "real" means a production system, as opposed to my laptop, a play VM etc etc :-)

It all went relatively smoothly except for one interesting thing, that I can’t 100% say was caused by the upgrade, but it would appear to be the case.

After the upgrade, our scheduler external jobs started failing.  A quick look in the alert log revealed:

Sun Jun 29  (more...)

SQL to find World Cup matches with comebacks

Lucas Jellema is writing a great series on SQL applied to the World Cup of football / soccer. In the article about finding matches with comebacks, he challenged readers to “find ‘dramatic comebacks’ where a team was two goals behind at some stage and yet managed to win the game.” Here is my reply, since replying […]

Employees Who Stay In Companies Longer Than Two Years Get Paid 50% Less

I came across an interesting article Employees Who Stay In Companies Longer Than Two Years Get Paid 50% Less and thought to share with you.

Let’s use the rule of 72 as an example.

Basically, the rule of 72 is a simple method of determining the number of years an investment will double by dividing 72 by the rate of return.

With a 4% annual salary increase, salary will double in 18 years (72/4).

With an (more...)

Sam Alapati’s 12c OCP upgrade book includes test software with key DBA skills

Sweet!  I just installed the software from the CD that came with Sam Alapati’s book related to the OCP 12c upgrade exam and found that it has questions related to the key DBA skills section of the test.  Now I feel good about my test preparation materials.  The first time I took the test I didn’t have this degree of guidance on what to study, especially on the key DBA skills section.

(more...)

Caution: hot patches

For many Oracle database patches there is an option to apply them “online”, i.e. without stopping the database and related services (listener, ASM etc.).  This is very convenient when downtime is impossible or difficult to arrange. However, this convenience comes at a certain price, including some performance penalties. Such side effects of hot patching are not well understood, even by Oracle support engineers.

There is a MOS note 761111.1 where in addition to (more...)

AWR thoughts

It’s been a week since my last posting - so I thought I’d better contribute something to the community before my name gets lost in the mists of time.

I don’t have an article ready for publication, but some extracts from an AWR report appeared on the OTN database forum a few days ago, and I’ve made a few comments on what we’ve been given so far (with a warning that I might not have time to follow (more...)