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Saturday, March 29, 2008

Do certifications always prove you're qualified to do the job?

Recently, I have come to the understanding that many certs fail to really certify whether or not someone can truly master material and do an effective job. There are quite a few individuals who are just very good test takers or students, if you will, and they study very hard or take expensive 'crash-courses' to help them pass with a high score.

There are a very few amount of certifications that I believe don't fail however. I can honestly say I have NEVER met someone that became an 'Oracle Master' that really wasn't at least a 7/10 on a 10-point scale. (Most DBAs being 3, 4 or 5.) Someone like Tom Kite or Kevin Loney being around the 10 range. This certification, of course, requires you to take hands on labs that are very difficult and stressful, along with prerequisite certifications and courses.

On the other hand, a very popular certification that seems to garner a lot of attention is PMI's PMP cert. This is for project management. Unfortunately, employers drool over this certification. PMI tried to do an extensive job of screening out people that are even allowed to TAKE the exams by having you fill out how much management work you've done, references, companies, and the whole 10 yards. Unfortunately, employers seem to feel that this means PMI has cleared this person as a top proj manager, and they don't have to have their own proven, top level project managers interview them on their PM skills and abilities.

Because of this, you have people that have 'hacked' their way through the PMI process unfairly by barely qualifying or by manipulating the system, then they take expensive crash courses, and they pass with a high score- BUT they have never truly managed a highly stressful and big-money project! They sometimes even ignore the holy trinity of constraints- resources, time, and project scope!

Does this mean a cert like the PMP is junk? Absolutely not. But it needs to be taken cautiously, and not frivolously. Interview these PMP's with your own proven top-level PMPs and see if they really can pull their weight. If you have a PMP with 20 years experience, vs one with 8-10...well, you can do the math.

Do your homework ahead of time, and make sure the PMP you're hiring is proven- and not just from the references THEY give you! Putting an PMP in charge of a project that could jeapordize the project is very dangerous, and you sadly don't realize this until the project is hitting it's critical points!

Friday, March 28, 2008

SQL Developer and the TNS Connection Type Selection

I will be exploring this much further soon, but suffice it to say, sometimes when you install SQL Developer or other Oracle tools, they look at the most recent Oracle home from a new Product install. For example, I installed OWB, and it had a new home. This actually overwrote some of the paths in the Operating System, and defaulted that home as the 'main' home.

Well a tool like SQL Developer loads a nice TNSNAMES.ora listing of all your database connections and it searches through that default home. If it looks at a new home that doesn't have those listings, you drop down will have no available connections!

A VERY easy way to fix this is to launch the universal installer, look at all installed products, and while looking at the oracle homes on your box, you can use the up and down arrows on the right panel to 'rank' or put a certain oracle home as the 'main' or default home. Doing this, I then put my original database home as the default. I restarted SQL Developer, and bingo! It then read the right oracle home and the right TNSNAMES.ora entry and populated the drop down.

Not bad!

Wednesday, March 26, 2008

Oracle Warehouse Builder OWB 10gR2 Tutorial for you!

Here's a set of slides with some basics of OWB for beginners to look over. I know Oracle has some Oracle By Example tutorials that are 'OK' at best. This is another look at the tool for you to learn from. Hopefully these will fill in some gaps as the documentation is not so great, there are no OWB books, and there is not as much useful information about this product compared to other Oracle products.

Tuesday, March 25, 2008

What the Oracle Database can do for your Data Warehouse

There are many MANY times I write a particularly difficult query or PL/SQL package and I realize that I am re-inventing the wheel. Reinventing the wheel = BAD. (unless there is something nifty in there that hasn't been done before).

I wanted to make a quick list of links to various tutorials, articles, and direct bits of Oracle docs that will get you to understand and learn some of the database provided tools that can make your SQL writing and Data Warehouse tuning and building much easier. Some of these tools are not always easy to use the first time, but they will be easier to learn than forcing yourself to build them (or rebuild the wheel).

I'll post the 10g features for now. I'll try to get back and post the 11g features and how they work as well. Suffice to say, the 10g features are in 11g and some are enhanced. These can really save you some time. Usually the hard concepts and difficult things you seek to do are already here.
For example, how many times have you had to do some pretty tough hierarchical processing (parent-child relationships) but never used the SQL connect-by query clauses?? These parent child relationships are extremely common in a Data Warehouse.

SQL Model Calculations
The MODEL clause enables you to specify complex formulas while avoiding multiple joins and UNION clauses. This clause supports OLAP queries such as share of ancestor and prior period comparisons, as well as calculations typically done in large spreadsheets. The MODEL clause provides building blocks for budgeting, forecasting, and statistical applications.

Materialized View Refresh Enhancements
Materialized view fast refresh involving multiple tables, whether partitioned or non-partitioned, no longer requires that a materialized view log be present. The second link I provide here is particularly useful because it has screen shots and walk throughs to help you with MVs. Getting MVs to work well with fast refresh can take a little patience with all of their prerequisites!

Query Rewrite Enhancements
Query rewrite performance has been improved because query rewrite is now able to use multiple materialized views to rewrite a query.

Partitioning Enhancements
You can now use partitioning with index-organized tables. Also, materialized views in OLAP are able to use partitioning. You can now use hash-partitioned global indexes. I also wrote a nice article in the IOUG BIWA (business intelligence, warehousing, and analytics) SIG's newsletter on the 11g database enhancements to partitioning, if you want to dig up their publications!


Change Data Capture
Oracle now supports asynchronous change data capture as well as synchronous change data capture.

ETL Enhancements
Oracle's extraction, transformation, and loading capabilities have been improved with several MERGE improvements and better external table capabilities.

Thursday, March 6, 2008

Should I buy an iPhone...once again-

I merely wanted to add this link. I have thought for a long time that this device lacked some enterprise level authority, and it looks like they will address that with the next release.

Check it out at this link to read the summit and SDK dicsussions...link

Peronally, this goes a long way for me...using VPN, exchange sync'ing, that is some decent thought there!

I might get one (when the price is under $500!)