Rittman Mead Blog - Data Warehousing

Rapid development using OBI EE (and what about the Data Warehouse?)

We are often told that one of the benefit of OBI EE is the speed and ease of development. Data sources can easily be added into the system, users can then quickly build queries and the results are easy to distribute. While I completely support this, to me this leaves

Technical

Dates and times comment

A few days ago, Farooq posted some comments on an old post of mine [https://www.rittmanmead.com/blog/2007/06/21/status-changes-over-time/]. The final comment in our exchange concerned storing activities in our data warehouse by time (actual hour and minute). This is quite a common requirement, especially where

Technical

Cube Organized Materialized Views

Yesterday, Mark mentioned [https://www.rittmanmead.com/blog/2008/03/25/new-white-paper-on-cube-organized-materialized-views/] a new Oracle white paper on Cube Organized Materialized Views - now that is a bit of a mouthful and shouts out to be made COMV or something equally short and saving of typing. I say that because

Technical

Data Warehouses are not dead, yet

One of the reasons that I left my old job to work with Rittman Mead Consulting was to get back to technology. Don't get this wrong, I really did enjoy managing people and having responsibility for a BI practice, but that was at the expense of involvement in

Technical

OLAP and summary management

So, why is someone who normally writes about data warehouses going to talk [http://www.collaborate08.com/collaborate08/] about Oracle OLAP, and in particular, cube organized materialized views? I could run out the argument that I work in a BI consultancy and none of us here at Rittman Mead [http:

Technical

Almost started OLAP 11g...

The proposal deadline for the upcoming Collaborate 08 was shortly before I was to leave my old employer - it was already known that I would be leaving them to join Mark and Jon (and possibly, it was known before Rittman Mead Consulting existed!) so it came as no real

Technical

Quality thoughts as I continue to chill out

Over at another Blog, Beth [http://datageekgal.blogspot.com/2008/01/data-quality-changes-large-and-small.html] notes that she is editor of the month for the Carnival of Data Quality. When It comes out I urge you to take a look. With those strange quirks of global IT companies Beth and I once

Technical

Used unused indexes

One of my old customers had a data warehouse with a three-area design model: a staging area for data load/cleanse, a third normal form (or more 3-NF-like than dimensional) raw data layer and a denormalised dimensional layer containing aggregated data for reporting. They ran a retail business and one

Technical

A flat world

A lot of data warehouses get some (if not all) of their data feeds through data files; in fact I can't recall a recent project where at least one feed from an external system did not arrive as some form of flat file. I have had customers whose

Technical

BI information security

These days there are a wealth of restrictions or regulations (SOX, UK Data Protection Act to name but two) on data access and coupled with the simple commercial need to hide sensitive information that means unfettered access to data warehouse data is a thing of the past. Fortunately products such

Technical

Winding down

In addition to moving my responsibilities to other managers, I have been tying up the odd technical loose end. During the recent upgrade to 10gR2 for one of our DW customers we noticed a frequent query that queried for raw sales for a named customer over a rolling 12 week

Technical

Converting partition views to partitioned tables

A few days I was talking to a customer who has a legacy data warehouse, designed back in Oracle 7.3 days which relies extensively on partition views as a way of handling the volume of data involved (basket level sales from a national high-street chain). Over the years the

Technical

Bye-bye Oracle 9.2

Well the detailed planning for a customer's data warehouse upgrade paid off. We kept mainly to plan until the customer tried using their query tool. We then spent what seemed an age, late at night, tracking down a problem which almost had the customer deciding to revert to

Technical

Data-centric BI trends

I managed to miss Mark Rittman's recent keynote addresses in two locations this week, but I did take a look at the slide deck and the blog [https://www.rittmanmead.com/blog/2007/10/05/five-oracle-bi-trends-for-the-future/] post. Mark is making five very sound points on the Oracle BI

Technical

Table compression

As I mentioned yesterday I was in London (in fact in the shadows of Westminster Abbey and the Houses of Parliament) today for the UK OUG BIRT SIG meeting. The venue was also shared by a UK OUG directors meeting so I got the opportunity to chat to Peter Robson

Technical

More on the 9.2 to 10.2 upgrade

But first. It's good to see that two bloggers in the Washington DC area are back on-line. Welcome back Tom [http://tkyte.blogspot.com/] and Sponge [http://oraclesponge.wordpress.com/] A few posts ago I mentioned [https://www.rittmanmead.com/blog/2007/08/31/upgrading-to-10g-ok-im-a-bit-behind/] my final 9

Technical

Meetings and other stuff

First up in this hotch-potch (or is it hodge-podge?) is a reminder of a BI meeting in London in a few weeks time; Tuesday September 25 in fact. The UKOUG BIRT SIG meeting [http://ukoug.org/calendar/show_event.jsp?id=2895] (wasn't BIRT SIG a Punk Rocker?

Technical

Upgrading to 10g - OK, I'm a bit behind

At long last, my final data warehouse customer on Oracle 9 is moving on to 10g. It has been a somewhat protracted move as for reasons of vendor support certification we had to adopt a specific order of refreshing their whole technology stack. That's not to say we

Technical

Reading time - Oracle 11g

There you are - I've mentioned it. But I have not downloaded it yet. One of the things I do with any new release is to read some (no, not all) of the documentation. The new features documentation, of course, is a given and enough of the of

Technical

Moving partition statistics

Over in another place [http://oracledoug.com/serendipity/index.php?/archives/1306-Full-Volume-Database-Refresh-Part-3.html] , Doug Burns has been writing on the joys of reproducing a full size database as test instance. He has even (graciously) put up with my wittering about things that not relevant to his articles. So as not

Technical

Oracle Partitioning 2007

I see that Oracle have posted [http://www.oracle.com/technology/products/database/oracle11g/index.html] a series of white papers on the soon to arrive 11g release, the one on partitioning [http://www.oracle.com/technology/products/bi/db/11g/pdf/partitioning-11g-whitepaper.pdf] caught my eye. But first an

Technical

Playing Around with Star Transformations and Bitmap Indexes

I’ve been doing some work this week with a client in London, who wants to put together a reporting data mart based on Oracle Database 10gR1. Although they and I were fairly sure a dimensional database design using bitmap indexes and star transformations would give them the query performance

Technical

Look Before You Leap

A recent post on Howard Rogers' blog around the hype and enthusiasm around the launch of Oracle 11g [http://www.dizwell.com/prod/node/881], together with some feedback I got during the review process for my OU seminar slides, got me thinking about how we sometimes rush in

Technical

I know that tune

Certain solitary acts give me great pleasure. Oddly, I consider the intellectual challenge of getting some of my customers' queries to fly a solitary act, it's me against the database. Or perhaps me against the customer. I have been working on a set of poorly performing queries

Technical

Smoke Testing with OWB

I have been putting together some thoughts on Agile Development techniques for a paper for the BIWA event later in the year. I have seen a couple of articles on Agile development notably on the Amis blog, here [http://technology.amis.nl/blog/?p=1971], in the Oracle space, so