Feed aggregator

The X (Path) File

Java 2 Go! - Fri, 2010-05-07 19:48
by Eduardo Rodrigues This week I came across one of those mysterious problems where I had some test cases that needed to verify the content of some DOM trees to guarantee that the test went fine. So,...

This is a summary only. Please, visit the blog for full content and more.
Categories: Development

Time Dimensions with Hourly Time Periods

Keith Laker - Thu, 2010-05-06 08:26
I was working on an application last week that required time series analysis at Hour, Day, Month, Quarter and Year levels. Two interesting things came out of this application.

First, a little implementation detail. The data was supplied in the fact and dimension tables at the Hour level with a TIMESTAMP data type. As you might expect then, there were time periods at the hour level such as:

02-JAN-10 10.00.00.000000000 AM
02-JAN-10 11.00.00.000000000 AM
02-JAN-10 12.00.00.000000000 PM
02-JAN-10 01.00.00.000000000 PM
02-JAN-10 02.00.00.000000000 PM

In my first attempt at building the time dimension I loaded hours directly from TIMESTAMP data type. In that case, the members at Hour level were loaded into the dimension stripped of the hour (e.g., 02-JAN-10). Since this isn't what I wanted, I converted the hours into a CHAR as follows:

CREATE VIEW time_dim_view AS
SELECT
TO_CHAR(hour_id, 'DD-MON-YYYY HH24') AS hour_id,
TO_CHAR(hour_id, 'DD-MON-YYYY HH24') AS hour_desc,
hour_time_span,
hour_id AS hour_end_date,
.. and so on.

This gave me dimension members at hour as follows:

01-JAN-2010 00
01-JAN-2010 01
01-JAN-2010 02
01-JAN-2010 03
01-JAN-2010 04

That worked just fine. I did the same for the descriptions (so that they would be more easily readable by end users) and added a corresponding column to a fact view so that the time view and fact view joined correctly on the TO_CHAR(...) columns.

For the TIME SPAN attribute, I used a fractional value of DAY (0.041667, which is 1/24th of a day). I read the DATETIME into the END DATE attribute as is (no conversion required). From there on, everything worked perfectly (cube builds, time series calculations, etc).

If you happen to look at the END DATE attribute from the OLAP DML side, be sure to wrap the END_DATE object in a TO_CHAR function so that you see the hours. Otherwise, you will see only the day in most cases (it depends on the NLS_DATE_FORMAT setting for the session). For example:

REPORT DOWN TIME TO_CHAR(TIME_END_DATE 'DD_MON_YYYY HH24')

The other thing that was interesting has more to do with the application design. As so often happens, the customer was inclined to build one cube with all history at the hour level (two years of history). When examining the reporting requirements, however, it turned out that hour level analysis very rarely occurs more than 2 month back. Almost all of the reporting looking back over the two years was at the day level or higher (that is, not hourly level reporting).

We could have built the one cube (two years, hour and higher), but most of the processing of hour level data would have been a waste because users don't look at the older data at that level. Instead, we built a very efficient application with two cubes. One cube contained only three months of data at the hour, day, month, quarter and year levels. Another cube contained two years of history starting at the day level.

Presentation of the data is mostly done using Oracle Business Intelligence Enterprise Edition(via SQL to the cube). Some reports examine hourly level data. Other reports examine more aggregate data over longer time periods. Time series calculations (e.g., period to date, moving average, etc.) were added to both cubes and made available in the OBIEE reports.

Occasionally, a user will want to drill from day to hour more than three months back. To support this, OBIEE was set up to drill from day (in the two year cube) to hour in the fact table. The only compromise was that the time series calculations of the cube were not available when drilling to hour in the fact table. That didn't matter to these users.

From the end user perspective, the fact that there were two cubes instead of one (as well as a fact table) was completely irrelevant since OBIEE presented all data in reports in a single dashboard. From a processing perspective, the system was much more efficient and manageable as compared to the single big cube approach.

It is very worthwhile to keep this lesson in mind when you design your applications. Pay careful attention to reporting requirements and build cubes that meet those requirements. You can tie multiple cubes together in a tool such as OBIEE. This approach is often much better then building a single cube every level of detail.

In this case, the example is about what level of detail is in which cube. The same concept applies to dimensions. You might find it much more efficient to build Cube 1 with dimensions A, B, C and D and Cube 2 with dimensions A, B, E and F rather than one big cube with all dimensions.
Categories: BI & Warehousing

Berkeley DB Java Edition 4.0.103 Available

Charles Lamb - Mon, 2010-05-03 02:19

We'd like to let you know that JE 4.0.103 is now at http://www.oracle.com/technology/software/products/berkeley-db/je/index.html. The patch release contains both small features and bug fixes, many of which were prompted by feedback on this forum. Some items to note:


  • New CacheMode values for more control over cache policies, and new statistics to enable better interpretation of caching behavior. These are just one initial part of our continuing work in progress to make JE caching more efficient.

  • Fixes for proper cache utilization calculations when using the -XX:+UseCompressedOops JVM option.

  • A variety of other bug fixes.

There is no file format or API changes. As always, we encourage users to move promptly to this new release.

Bicycle Diaries - I

Vattekkat Babu - Mon, 2010-05-03 00:41

Once I entered work life, physical activity was pretty much restricted to keyboard and mousing. I hate running. I like only Cricket, Badminton and Table Tennis for sports. All need others to be available. I love to swim, but in Bangalore where I stay, it is not very convenient. I used to enjoy cycling when I was in school. Some six months ago, bought one (Hercules ACT 104). Rode it on and off for 4-5 short trips. While it is enjoyable, I never stuck to a routine. Since I am on vacation now, I thought I will attack it as a 2 week project and see if I can actually do it.

If you are a fitness freak, don't bother. I am talking about 5km as a goal - if you routinely do 15km+, you might find this quite boring.

Flooding in Tennessee

Michael Armstrong-Smith - Sun, 2010-05-02 22:54
As many of you will be aware there has been unprecedented and extensive flooding throughout Western and Central Tennessee this weekend. My home town is Cookeville which lies about 75 miles to the east of Nashville which as you know is one of the worst hit areas with well over 14 inches of rain in the last 48 hours. To everyone who has asked after me and my family I just want to say thank you and to let you know that we are safe. Even though there is water all around the area with trees down and rivers over their banks our property, because it is at a higher elevation than most, is safe.

Unfortunately, the same cannot be said for the rest of the state. Not so very far away there are lots of houses under water and I know that my home state is being devastated even as I write. For anyone who has ever been here you will know that this is one of the most beautiful parts of the United States which makes it even harder to take. While Tennessee may not be the richest state in the union the people here are hard working, God loving, gentle folk who didn't need this.

If you have the opportunity to donate anything to a relief effort, should one be organized, please do so. At the very least, please keep the people in this area in your thoughts and prayers as you go to sleep tonight.

More than Iron Man - Oracle and Marvel

Peter O'Brien - Fri, 2010-04-30 09:23
At the beginning of April 2010, Oracle, using the buzz around the release of Iron Man 2, kicked off a worldwide advertising campaign focused on introducing the powerful combination of Oracle and Sun. This includes old school billboards and commercials on a variety of old and new media platforms...

All this makes for some fantastic visuals, but how exactly is Marvel using Oracle? The list of Oracle products being used by Marvel is diverse:

  • Oracle E-Business Suite, including Financials, Human Resources, Self Service HR, Manufacturing and Incentive Compensation
  • Oracle Business Intelligence Suite
  • Oracle Configurator
  • Oracle Enterprise Content Management Suite (formerly Stellent)
  • Oracle Insight
Further information on how Marvel is able to keep track of inventory, and manage the budget on epics like Iron Man, is revealed in Support for Superheroes, Avengers, Assemble! and Marvel Entertainment Grows its Business with Oracle (video)

NVARCHAR2 versus VARCHAR2

Michael Armstrong-Smith - Thu, 2010-04-29 15:02
I've been coming across more and more databases using NVARCHAR2 instead of the more usual VARCHAR2 data type and found some issues.

First, I had issues inserting data from an NVARCHAR2 column into a table where the corresponding column in the other table has a data type of VARCHAR2.

Second, I had an issue joining tables together where the same column was defined with a different data type, one being NVARCHAR2 and one being VARCHAR2.

Here is the way I solved these issues:

Inserting NVARCHAR2 into VARCHAR2
If you try inserting data from an NVARCHAR2 column into a table where the corresponding column in the receiving table is defined as VARCHAR2 you will get a character set mismatch error. You will need to use the TRANSLATE USING command, like this:
  • TRANSLATE(nvarchar2 USING TABLE1.NVARCHAR2_COLUMN) INTO VARCHAR2_COLUMN
Joining NVARCHAR2 to VARCHAR2
If you try creating a join using

WHERE TABLE1.NVARCHAR2_COLUMN = TABLE2.VARCHAR2_COLUMN

you will get an error. You will need to do this:

WHERE TO_CHAR(TABLE1.NVARCHAR2_COLUMN) = TABLE2.VARCHAR_COLUMN

What's new in OWSM 11gR1 PS2 (11.1.1.3.0) ?

Vikas Jain - Wed, 2010-04-28 03:21
Oracle Fusion Middleware 11gR1 PS2 (Patchset 2) aka 11.1.1.3.0 is released and generally available now.

What's new in OWSM 11gR1 PS2 (11.1.1.3.0)?
  • Agent for OSB 11gR1
  • Enhanced integration for WLS JAX-WS web services (centralized policy mgt, policy attachment through EM, policy advertisement in WSDL, and policy monitoring)
  • IBM DB2 certification of MDS backed policy store
  • WS-Security + WS-AT combination support
  • Enhanced Test-to-Production for policy attachments using deployment plans
Also see,

The Next RAC, ASM and Linux Forum. May 4, 2010 Beit HP Raanana

Alejandro Vargas - Tue, 2010-04-27 18:39

The next RAC, ASM and Linux forum will take place next week, you are still on time to register : Israel Oracle Users Group RAC,ASM and Linux Forum

This time we will have a panel formed by Principal Oracle Advanced Customer Services Engineers and RAC experts Galit Elad and Nickita Chernovski and Senior Oracle Advanced Customer Services Engineers and RAC experts Roy Burstein and Dorit Noga.

They will address the subject: 5 years of experience with RAC at Israeli Customers, lessons learned. It is a wonderful opportunity to meet with the people that is present at most major implementations and helped to solve all major issues along the last years.

In addition we will have 2 most interesting Customer Presentations:

Visa Cal DBA Team Leader Harel Safra will tell about their experience with scalability using standard Linux Servers for their mission critical data warehouse.

Bank Discount Infrastructure DBA Uril Levin, who is in charge of the Bank Backup and Recovery Project, will speak about their Corporate Backup Solution using RMAN; that includes an end to end solution for VLDBS and mission critical databases. One of the most interesting RMAN implementations in Israel.

This time I will not be able to attend myself as I'm abroad on business, Galit Elad will greet you and will lead the meeting.

I'm sure you will enjoy a very, very interesting meeting.

Beit HP is located at 9 Dafna Street, Raanana

Best Regards

Alejandro


View Larger Map

Categories: DBA Blogs

UKOUG – Exciting News for the Northern Server Tech Community...

Lisa Dobson - Fri, 2010-04-23 14:12
Not only is it time for the Northern Server Tech Day in Leeds next week, which is exciting enough, but the UKOUG is now looking to form the Northern Tech SIG.The UKOUG has been running the NST as an annual one day event for the last 5 years, and it is now time to create a SIG to focus on delivering Server Tech content across the North of England on a regular basis.In order to get this off the Lisahttp://www.blogger.com/profile/16434297444320005874noreply@blogger.com6

JHeadstart 11g Evaluation Version Now Available!

JHeadstart - Thu, 2010-04-22 22:22

Oracle JHeadstart 11g went production two months ago. As of today, a fully functional evaluation version is available for everyone. It can be installed through the JDeveloper Check for Updates facility, by choosing the Open Source and Partners Extensions Update Center.
The evaluation version contains the same functionality as the production version, with two limitations: the JHeadstart Forms2ADF Generator is not included, and the workspace cannot contain more than 10 View Objects.

The comprehensive JHeadstart tutorial initially written by Steve Muench has been revised and extended for release 11g. If you quickly want to get insight in the added value of JHeadstart 11g, then the tutorial is the place to start. I believe that even seasoned ADF developers are likely to be impressed by the functionality, productivity gains and best practices JHeadstart 11g brings to the table, and which are highlighted in this tutorial.

The JHeadstart Product Center on OTN includes a lot of new material, including an updated feature list, new overview presentations and online demonstrations of the JHeadstart Forms2ADF generator.

Categories: Development

Home thoughts on aviation

Pete Scott - Sat, 2010-04-17 08:48
Today my normally silver car has a more golden-bronzy tinge, or a thin film of volcanic dust. Part of Iceland is now travelling around the streets of Milton Keynes attached to my car, a sort of grimy hitch-hiker. I should not really know about the dust on my car as I should not be in […]

Oracle's Cloud Computing Events

Peeyush Tugnawat - Wed, 2010-04-14 12:20

Here is a useful link to Oracle full day events on Cloud Computing worldwide

http://www.oracle.com/events/cloudcomputing/index.html

 

Other Oracle Cloud Computing Resources

Oracle's Cloud Computing Products and Services

Oracle's Cloud Computing Resource Center

 

Others

My Previous Post about Cloud Computing

Oracle's Cloud Computing Events

Peeyush Tugnawat - Wed, 2010-04-14 12:20

Here is a useful link to Oracle full day events on Cloud Computing worldwide

http://www.oracle.com/events/cloudcomputing/index.html

 

Other Oracle Cloud Computing Resources

Oracle's Cloud Computing Products and Services

Oracle's Cloud Computing Resource Center

 

Others

My Previous Post about Cloud Computing

Certain things in this world

Virag Sharma - Tue, 2010-04-13 09:03

"In this world nothing can be said to be certain but death and taxes."
--Benjamin Franklin

Categories: DBA Blogs

Oracle Enterprise Linux 5.5 Installation Media Now Available

Sergio's Blog - Tue, 2010-04-13 00:10
OEL 5.5 was released on ULN on April 5, 2010 and on public-yum.oracle.com shortly after. Now you can also download the installation DVD or CDs from edelivery.oracle.com/linux.
Categories: DBA Blogs

Oracle + Sun + Iron Man 2: Awesome!

Eduardo Rodrigues - Fri, 2010-04-09 15:22
A cool Iron Man 2 teaser...

This is a summary only. Please, visit the blog for full content and more.

Oracle + Sun + Iron Man 2: Awesome!

Java 2 Go! - Fri, 2010-04-09 15:22
A cool Iron Man 2 teaser...

This is a summary only. Please, visit the blog for full content and more.
Categories: Development

Changing the hostname when Oracle is already installed

Klein Denkraam - Wed, 2010-04-07 06:51

Nothing new here, just a reminder for myself where I can find a short, concise description of how to do this. I use it mainly when cloning VMWare Virtual Machines. Safes the trouble of reinstalling Oracle.

Thanks must go to Scott van Vliet, the owner of the blog entry that explains it all.


Dynamic Re-Mastering in 11g

Fairlie Rego - Wed, 2010-04-07 06:19
This is a follow-up on a post from last year

http://el-caro.blogspot.com/search/label/10g%20RAC%20DRM

Node 1
========
SQL> create table obj as select * from sys.obj$;

Table created.

SQL> select object_id,owner,object_type from dba_objects where object_name='OBJ' and object_type='TABLE';

OBJECT_ID OWNER OBJECT_TYPE
---------- ------------------------------ -------------------
136388 REGOFA TABLE


SQL> select * from V$GCSPFMASTER_INFO where DATA_OBJECT_ID=136388;

no rows selected


Now we go to node 2 and manually master the object there...

Node 2
=========
SQL> oradebug setmypid
Statement processed.
SQL> oradebug lkdebug -m pkey 136388
Statement processed.
SQL> select * from V$GCSPFMASTER_INFO where data_object_id=136388;

FILE_ID DATA_OBJECT_ID GC_MASTERIN CURRENT_MASTER PREVIOUS_MASTER
---------- -------------- ----------- -------------- ---------------
REMASTER_CNT
------------
0 136388 Affinity 1 32767
1


Node 1
======

SQL> oradebug setmypid
Statement processed.
SQL> oradebug lkdebug -m pkey 136388
Statement processed.

Also Bug 5649377: REMASTER_CNT IN V$GCSPFMASTER_INFO IS NOT GETTING UPDATED
which I logged in 2006 is fixed in 11g

SQL> /

FILE_ID DATA_OBJECT_ID GC_MASTERIN CURRENT_MASTER PREVIOUS_MASTER
---------- -------------- ----------- -------------- ---------------
REMASTER_CNT
------------
0 136388 Affinity 0 1
2

As you can see the remaster_cnt is correctly set to 2 above
SQL> select * from X$KJDRMAFNSTATS;


ADDR INDX INST_ID DRMS AVG_DRM_TIME OBJECTS_PER_DRM
---------------- ---------- ---------- ---------- ------------ ---------------
QUIESCE_T FRZ_T CLEANUP_T REPLAY_T FIXWRITE_T SYNC_T RES_CLEANED
---------- ---------- ---------- ---------- ---------- ---------- -----------
REPLAY_S REPLAY_R MY_OBJECTS
---------- ---------- ----------
0000000060016FC0 0 1 104 11291 186
3219 28 1622 1302 4589 510 0
26 191959 2


SQL> select count(*) from V$GCSPFMASTER_INFO where current_master=0;

COUNT(*)
----------
2


DRM info is now also available in AWR tables via DBA_HIST_DYN_REMASTER_STATS

Also the following event can be used to trace DRM information

Event can be turned ON dynamically

SQL> alter system set events '10430 trace name context forever, level 10';

System altered.


*** 2010-04-07 21:02:23.831
Begin DRM(245) (swin 0) - AFFINITY transfer pkey 136388.0 to 2 oscan 1.1
kjiobjscn 1
ftd (30) received from node 1 (8/0.0.0)
all ftds received

* kjxftdn: break from kjxftdn, post lmon later

Event can be turned off
SQL> alter system set events '10430 trace name context off';

System altered.


Also the LMON and LMS trace files contains DRM related info

Although I have seen a lot of issues in 10G and turned off DRM in many cases I haven't seen any such issues
in 11.2 so far

Pages

Subscribe to Oracle FAQ aggregator