Voice of the DBA

Tag: career

Data Analysis Techniques
This is part of a series on my preparation for the DP-900 exam. This is the Microsoft Azure Data Fundamentals, part of a number of certification paths. You can read various posts I’ve created as part of this learning experience.

I didn’t think much of this bullet on the DP-900 skills document: describe analytics techniques.

Learn these concepts. They are definitely part of the knowledge needed. This is a part of some MS Learn courses, like this one.

Descriptive Analytics

Descriptive analytics have to do with describing what the data shows. In a report or visualization, we are reporting data to the user. An example of this is showing the top 10 products according to sales.

These are explanatory analytics and think about that in the test. Are we explaining something.

Diagnostic Analytics

A diagnosis is an explanation of why something happened. Diagnostic analytics help explain the reason that something occurred. We might look at the top 10 sales against advertising for products and determine that more advertising shows higher sales.

In the link above from MS Learn, what we typically do here is identify some anomaly or thing we want to explain, get data related to this, and then use some statistics to find a relationship.

Predictive Analytics

As you might guess, this type of analytics relate to the future. We are looking to predict what will happen. An example might be forecasting future demand for services.

When you see a request to predict, forecast or extrapolate, think predictive analytics.

Prescriptive Analytics

This type of analysis was a little harder for me to understand or grasp. I get the general idea, but in prep I missed this one a few times. Prescriptive analytics are developing a prescription for how to change something.

An example might be if I want to find where to cut costs to impact profit, I am looking for a set of things to change. I need a prescription on what will help me achieve my goal.

In relation to the exam, this has to do with aiming for a goal (10% more or 12 less) and how to reach that goal. If you see specific numbers, usually that relates to a goal and prescriptive analytics.

Cognitive Analytics

This type of analysis has to do with thinking. In data analysis and computing, usually I think ML, AI, or some other type of data mining. This can be deriving conclusions or inferences from data, but the blend between this and the descriptive/diagnostic stuff becomes blurry.

If you need to do speech to text or video transcription or image recognition, think cognitive.

Summary

This is how I viewed this techniques on the exam when answering questions:
- Descriptive
  – What
- Diagnostic
  – Why
- Predictive
  – What will happen
- Prescriptive
  – What do I do
- Cognitive – Learning about data in new ways
March 2, 2022
Goal Progress for Feb 2022
I set goals at the beginning of the year, and I’m tracking my progress in these updates during 2022.

February became more of a work month for me, and a somewhat busy month outside of work with life. I didn’t do enough on my career, and am more stalled than I’d like. I let distractions take over more than I should, and I felt a bit bad at the end of the month, rushing through some things the last week of Feb to make a little progress.

I’m slowing down, but at least I did something. I’m lowering the grade because I just didn’t do enough.

Grade: C+

Here are the goals:

Work
- DP-900 – Passed
- DP-300
  – Stated studying, practice tests around 60% correct
- Demo with SQL Server – 5%
- Demo with PostgreSQL – 0%
- Demo with MySQL – 0%
- Feedback book – 72%
- Good Strategy/Bad Strategy – 0%
Personal

I made a slight alteration here. I didn’t try to hook up to Google Sheets, but instead pasted in some data and started to try and get this moving.
- Link Google Sheets to Power BI – 0%
- Create Report – 0%
- Create Dashboard – 0%
- Get people using it – 0%
Community
- Support the Colorado groups by speaking twice and helping get one event set up
  – 33%
  - CO Springs event set up
- Speak at 3 other user groups outside of Colorado – 33%
  - Spoke at DBA Fundamentals group
- Support SQL Saturdays – Help get 10 events run in 2022
  - 3 scheduled, 2 more close
- Volunteer 4 days with Habitat – 0 days
March 1, 2022
Less is More

The world of Information Technology has changed a lot during my career, but in some ways, many things remain the same. There are still mainframes in use, and plenty of jobs. Lots of companies maintain their infrastructure in data centers, even though some are turning to private clouds for their infrastructure. There are plenty of jobs in that area as well.

There is a trend to consolidate resources into a bucket and then allocate those as needed for various applications and services. This is what mainframes do, albeit at a very high degree of reliability (and cost). The cloud seeks to replicate this, not with high reliability, but with redundancy, expecting systems to fail. In fact, plenty of the data centers these days involve a lot of similar hardware systems tied together with software, with failed systems being left in place rather than replaced.

This trend aims towards a lights-out data center, where humans don’t work inside the location with servers. As someone that used to keep a coat by my desk in the summertime for trips inside the locked “computer room”, it’s a welcome trend. While a few people might actually need to check a cable or service an AC or UPS unit, most of us these days never see the systems we work on, whether those systems are owned by our company or rented in the cloud.

This doesn’t mean that we won’t have as much work. In fact, I think that most of the trends in computing over the last three decades have opened up opportunities for workers. This article talks about some of those changes that allow workers to morph along with technology to tackle different aspects of similar jobs. I certainly expect that anyone who wants to improve their skills and adapt to the new data center of the future to have plenty of work.

This reminds me of a scene from Aliens, where workers use enhanced suits to load heavy crates. I think this is the type of future I see, where humans work alongside new technology rather than being displaced by it. The need for humans to monitor, manage, adjust, and configure software systems and physically work alongside high-tech software is not going away anytime soon. The more that we adapt new technology, the more it seems that we add humans to work alongside it in some new way.

Continue to learn, adapt, and adjust your skillset and you can remain employed for a long time.

Steve Jones

Listen to the podcast at Libsyn, Stitcher, Spotify, or iTunes.

February 28, 2022
Azure Redundancy for Storage

This is part of a series on my preparation for the DP-900 exam. This is the Microsoft Azure Data Fundamentals, part of a number of certification paths. You can read various posts I’ve created as part of this learning experience.

In a previous post, I discussed the makeup of Azure regions and Availability Zones. These are important concepts to understand how storage protection works. This post looks at the various redundancy types: LRS, ZRS, GRS, and GZRS and RA-GZRS.

Note: This isn’t directly on DP-900, but these concepts did help me understand better how the Azure options fit together.

As I discuss these, this infographic might help. Also, MS Docs has an article.

Local Redundant Storage – LRS

As it might imply, this means that your storage bits are copied synchronously to redundant storage in the local area. In this case, this means the data center where your storage is located. Your files (or VHD or whatever) is copied three times into separate locations. This means that your files can survive a single node (computer or disk) failure.

This also means you should forego software RAID for VMs or data files as there are already three copies that will acknowledge the write.

You do not get to pick which data center, just the region where the data center lives. This means your resource could be in any of the data centers in a region, but there are three copies.

Impressively, this gives you 11 9s of durability. However, a fire or major failure of a single data center might cause all your data to disappear.

You can use managed disks with LRS.

Zone Redundant Storage – ZRS

The next level of protection is ZRS, where you get three copies, but this time the copies exist in three parts of an Availability Zone. This is why the AZ must be inside a 2ms latency boundary. This way your files can be copied from data center to data center inside of the AZ.

In this way you achieve 12 9s of durability for your files. More importantly, if a single data center were to go offline, you would still have access to your files (or VHDs).

You can use managed disks with ZRS.

Geo-Redundant Storage – GRS

This is a type of redundancy that is between LRS and GZRS. In GRS, the primary data center implements LRS, with 3 copies of files in the single data center. This gives you protection against node failures.

A second copy, asynchronously, is made in a second region, where LRS is also implemented. This means 6 copies of your data, spread across 2 data centers, one in each of two regions. The image below shows this:

Note, the files in the secondary region are not accessible unless there is a failover. However, if you add RA-GRS, the read access equivalent, you can access files in either zone.

Geo-Zone Redundant Storage – GZRS

GZRS expands the ZRS storage to include a second region. You still get three copies in your primary region spread out across an AZ, but you also get three copies in a secondary region. These are replicated asynchronously as the latency between regions isn’t bounded closely enough for synchronous changes.

The secondary zone uses LRS for the copies. The difference between GRS and GZRS is the replication in the primary region.

GZRS is supposed to give you 16 9s of durability.

Read Access Geo-Zone Redundant Storage – RA-GZRS

With GZRS, there is more protection for your files, but you cannot access the files in the secondary region unless you fail over from the primary region. The customer or Microsoft can initiate this.

In some cases, you might wish that you could spread the read workload between the primary and secondary regions. With RA-GZRS, you can do this. Your clients can access files in the secondary or primary region.

Availability of Azure Storage Options

Not all Azure Storage options are available with the different redundancy options. In the redundancy article, there are two charts, I’ve reproduced below. This first one looks at the different redundancy options and which types of storage fit:

This next one shows that the different account types fitting in the options.

February 23, 2022