The Data Warrior

Changing the world, one data model at a time. How can I help you?

Archive for the tag “Data Modeling”

Early Christmas: The New #SQLDev Data Modeler is Here!

Thanks to the gang at Oracle for an early Christmas present – the newest version of Oracle SQL Developer Data Modeler (SDDM) is ready for download and use.

The best FREE data modeling tool on the planet just got better!

To be clear this is Early Adopter (EA) version 2 of SDDM 4.2. You can get it here right now!

#SQLDev Data Modeler New Features

Of course there are some bug fixes from EA1, but also some new features for you to enjoy:

Import from Oracle Database

  •   performance and filtering enhancements
  •   ability to define Oracle Client for thick connections
  •   view and materialized view driving query and columns now parsed and validated

Versioning

  •   improvements in performance
  •   new models are shown as a single node in pending changes window

Reporting

  • PDF reports allow diagrams to be embedded with links from diagram to details part into report
  • HTML report for tables now include diagrams

 

SQL Developer Data Modeler EA2 adds diagrams to HTML reports

#SQLDev Data Modeler HTML report with diagrams embedded

So go download and unwrap that present!

Cheers!

Kent

The Data Warrior

P.S. If you need training on Oracle Data Modeler, be sure to check out my online video training course along with my tips and tricks ebook. (HINT: Buy them now, and you may be able to deduct the cost from your 2016 taxes as an educational expense.)

Drill to Detail Podcast: Data Modeling, Data Vault, and Snowflake!

My good friend Mark Rittman has embarked on a new adventure as an independent analyst and consultant. As part of his new venture Mark started a new podcast series on iTunes that he calls Drill to Detail where he will feature interviews discussing a range of topics related to data warehousing, business intelligence, analytics, and big data.

I was honored to be asked to take part in this new venture and got to spend a hour with Mark a few weeks back recording what is now Episode 5 of the series. In this interview we talk about:

The podcast is about 60 minutes with each topic being about 20 minutes (so feel free to skip ahead if you are short on time). Please have a listen and let us know what you think in the comments below.

Cheers!

Kent

The Data Warrior

P.S. I will be speaking on these and related topics at a bunch of events over the next few weeks. Check out my speaking schedule and join me in person if you can!

Maintaining disabled FK’s, wisdom or farce?

A while back, I wrote a post about having FKs (foreign keys) in your data warehouse.

Well, a similar question came up recently on an Oracle forum with the above title. It is a fair question and it does surface fairly regularly in a variety of contexts (not just data warehousing).

Of course, as The Data Warrior, I felt is was my duty to respond.

The Question

Is there any reason to maintain a permanently disabled FK in the data model?  I’m not envisioning a reason to do it.  If it is not going to be enabled, then from my perspective, it would not make any sense to have it defined.  If anything, provide the definition of the relationship in the comment of the child column.

My Answer

Yes, by all means keep the FK please!

I see three good reasons for doing so:

  1. It is valuable metadata (& documentation). If somebody reverse engineers the database (say with ERWin or Oracle Data Modeler), the FK shows up in the diagram (way better than having to read a column comment to find out)
    Data Vault 2.0 Example

    A picture is worth a thousand words!

    .

  2. BI Metadata – If you want to use any sort of reporting or BI tool against the database, most tools will import the FK definition with the tables and build the proper join conditions. Way better than having someone guess what the join will be and then manually adding it to the metadata layer in the reporting tool. Examples that can read the Oracle data dictionary include OBIEE, Business Objects, COGNOS, Looker, and many others.(Note here that since the FK is not enforced on the remote databases, you might want to make sure these are treated as outer joins, lest you lose some transaction in the reports).
  3. The Oracle optimizer will use disabled constraints to improve query performance of joins. Again, this is metadata in the data dictionary which the optimizer can read. This is documented in the Oracle Data Warehouse guide and I have validated it on multiple occasions with Oracle product management.

While #3 applies specifically to Oracle, for other databases like MS SQL Server and Snowflake, #1 and #2 still apply.

Even if only one of the above is true for a given database, that, in my opinion, still justifies keeping the disabled constraint around.

Final Answer = Wisdom

What do you think? Feel free to comment below.

And please share on your favorite social media platform!

Model on!

Kent

The Data Warrior

 

One more time: Do we still need Data Modeling?

More specifically do we still need to worry about data modeling in the NoSQL, Hadoop, Big Data, Data Lake, world?

This keeps coming up. Today it was via email after a presentation I gave last week. This time the query was about the place of data modeling tools in this new world order.

Bottom line: YES, YES, YES! We still need to do data modeling and therefore need good data modeling tools and skills.

Snowflake with RI

A picture can say so much!

 

In order to get any business value out of the data, regardless of where or how it is stored, you have to understand the data, right?

That means you have to understand the model of the data. Even if the model (or schema) is not needed upfront to store the data (schema-on-write), you must discern the model in order to use it (schema-on-read).

It is (mostly) impossible to get repeatable, auditable metrics, KPIs, dashboard, or reports that bring value to the business without understanding the semantics of the data – which means you at least need a conceptual or logical model.

And if you want/need to join data from multiple source then you really have to understand each source or there is no way to properly join it all together to get meaningful results.

There are a few data cleansing, discovery,and “virtualization” tools out there that will help you figure out those relationships but they are expensive and mostly rely on standard data profiling techniques to find similar data objects across the sets and propose “relationships”. Some allow for the definition of fairly sophisticated matching rules including customizations. But a human still needs to figures those out, test, and validate the results.

In the end you still have to know your data.

One of the best ways to do that, in my opinion, is to model that data. Otherwise your data lake will likely become a data swamp!

So keep your data modeling tool and keep building your data dictionary with your business folks.

Final Stage Table

A good modeling tool can act as a visual data dictionary too!

If you agree with me, please share on social media!

#LoveYourData

Kent

The Data Warrior

P.S. If you need a good modeling tool, check out Oracle SQL Developer Data Modeler. And check out my books and training offering for SDDM on the blog sidebar.

Where is the Data Warrior Now?

Hi folks. Time to update y’all on some upcoming speaking engagements for this summer and fall.

Here are a few talks I have scheduled:

Houston DAMA 

When: August 9, 2016 1:30 PM

WhereBP Westlake Campus, Helios Plaza, Houston, TX

Topic 1: Harnessing the Elasticity of the Cloud for Analytics with Snowflake and Tableau

Topic 2: Agile Data Warehousing – Building a Virtualized ODS

Register: Houston DAMA Meetup

Agile Denver: BI Meetup #1 

When: August 17, 2016 5:30 PM

Where: Charles Schwab, Lone Tree, CO (Denver Tech Center)

Topic: Agile Data Warehousing – Building a Virtualized ODS

RegisterAgile BI Meetup

Agile Denver: BI Meetup #2

When: August 18, 2016 5:30 PM

Where: WebPT, Westminster, CO

Topic: Agile Data Warehousing – Building a Virtualized ODS

RegisterAgile BI Meetup

Enterprise Dataversity

EDV2016-ImSpeakingWhen: September 21, 2016 8:30 AM

Where: The Drake Hotel, Chicago, Ill

Topic: Data Warehousing in 2016 and Beyond

Register: Enterprise Dataversity

 

Utah Oracle Users Group (UTOUG) Fall Symposium

When: October 26, 2016

WhereSalt Lake Community College Miller Campus, SLC, Utah

Session #1Agile Data Warehousing: Using Oracle Data Modeler (SDDM) to build a Virtualized ODS

Session #2: Agile Methods and Data Warehousing: How to Deliver Faster

Session #3: Data Warehousing in the Real World

Register: UTOUG Registration – Coming Soon!

 

Southern Fried Agile

When: October 28, 2016

Where: Charlotte Convention Center, NC

Topic:  Agile Methods and Data Warehousing: How to Deliver Faster

Register: SFA Registration

 

East Coast Oracle (ECO) Users Conference

When: November 2 & 3, 2016

Where: Hilton North Raleigh/Midtown Hotel, Raleigh, NC

Topic #1Agile Data Warehousing: Using Oracle Data Modeler (SDDM) to build a Virtualized ODS

Topic #2: Data Warehousing in 2016

Register: ECO Registration

 

There are more talks in the planning process so be sure to check back.

Hope to see you at one of these events!

Love your data!

Kent

The Data Warrior

Data Warrior LLC

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