I use fio for all my I/O testing. Why not Orion from Oracle since almost all of my I/O testing and benchmarking has been geared toward Oracle? Several reasons
- super flexible – able to configure it for almost all types of test
- active community – updates almost every week, many by Jens Axobe (who wrote much of the Linux I/O layer)
- reliable – if there are problems, it’s open source and one can (more...)
A common criticism of PLSQL is that the "original" array datatype, now called associative arrays are perfect for passing stuff back and forth to 3GL environments (for example .Net), but canno be used within SQL natively, for example:
SQL> create or replace
2 package BLAH is
3 type num_list is table of number index by pls_integer;
4 type str_list is table of varchar2(30) index by pls_integer;
6 procedure ODP_PROC(n out num_list, s out str_list);
A rather odd performance issue happened at work a few days ago. All of a sudden, one of the databases started to work very slowly, and a quick look in ASH data showed that it was spending over 70% of its time waiting on “row cache lock” (not to be confused with “latch: row cache lock”).
It was a test database (184.108.40.206) on an overloaded server with non-standard configuratioin, so my initial reaction (more...)
Last week I’ve gotten a question on how storage indexes (SI) behave when the table for which the SI is holding data is changed. Based on logical reasoning, it can be two things: the SI is invalidated because the data it’s holding is changed, or the SI is updated to reflect the change. Think about this for yourself, and pick a choice. I would love to hear if you did choose the correct one.
I just finished reading Sam Alapati’s 12c OCP upgrade book for the first time and I really like it because of the content that it covered which I hadn’t discovered through my study of the Oracle manuals. Also, it did a good job explaining some things that Oracle’s manuals left unclear.
After reading each chapter I took the end of chapter test and got between 60% and 75% of the questions right. Next (more...)
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.
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'
If you like to compile pll file in R12, you can use frmcmp_batch command instead of using f60gen
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
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...)
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….
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...)
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...)
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),
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...)
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...)
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...)
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...)
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...)
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 […]
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...)