Tag Archives: Professional Development

Two key interview questions for SQL developer candidates

Leave a reply

Frequently in my career I’ve selected or helped select ETL and reporting professionals who need SQL skills. For some of those opportunities, placement firms returned resumes with interminable, and nearly identical, lists of technical achievements with excruciating unnecessary detail (paraphrasing: “Wrote SELECT statements using GROUP BY”, “Applied both inner and outer joins”). Before interviewing we typically ranked candidates in order of preference based on resumes. Candidates’ interview success bore little relation to resume-based rankings.

With some candidates I’ve encountered consistent pauses after fact questions, sometimes accompanied by keyboard clicks. They obviously used “think time” to look up answers on the internet. As a result, “fact” questions didn’t distinguish one candidate from another.

On the other hand, open ended questions worked well. I’ve written before that interviews should ask opinion rather than fact questions. Open ended questions or thought exercise, as opposed to fact questions, assess SQL skill level, are hard to quickly look up on the web, and have the added benefit of demonstrating a candidate’s reasoning and communication skills. Here are two of my favorite examples: Continue reading →

Resources for Working From Home: Tips and Gear

3 Replies

In our current “social distancing” situation, many are working remotely in a serious way for the first time. As one who’s worked full time from home for the past four years, and frequently before that, I thought I should share some tips based on experience. Below are my top three tips and then some of the gear that I’ve used to set up a comfortable workspace.

But first to sum it all up, WFH works well for me. On a team of folks mostly working from home, we are engaged and productive, and have developed what I hope are lasting relationships with each other, although we rarely see each other in person.

Here is what has worked for me:

  • Stick to a routine
  • Be available, productive, and communicative
  • Cultivate a non-work social life
  • Set up a comfortable workspace
  • Proactively balance child care and work*

Continue reading →

Two Design Principles for Tableau Data Sources

Leave a reply

It’s not unusual for talented teams of business analysts to find themselves maintaining significant inventories of Tableau dashboards. In addition to sound development practices, following two key principles in data source design help these teams spend less time in maintenance and focus more on building new visualizations: publishing Tableau data sources separately from workbooks and waiting until the last opportunity to join dimension and fact data.

Imagine a business team — let’s call it Marketing Analytics — with read-only access to a Hadoop store or an enterprise data warehouse. They gain approval for Tableau licenses and Tableau Server publication rights for five tech-savvy data analysts. After a few initial successes with some impactful visualizations, the team gathers steam. After a while the team finds itself supporting scores of published workbooks serving a few hundred managers and executives. In spite of generally sound practices, Marketing Analytics struggles to maintain consistency from one Tableau workbook to another.

Continue reading →

More on “Select Failed. [2646] No more spool space”

1 Reply

Also see the previous related post Escaping Teradata Purgatory (Select Failed. [2646] No more spool space)

Not too long ago I posted on how to avoid the dreaded “No more spool space” error in Teradata SQL. That post recounted approaches to restructuring SQL queries so that they would avoid being cancelled for using inordinate amounts of Teradata resources. Teradata is an immensely powerful, even if aging, database engine but it does little to help one not steeped in knowledge of its structure to use its resources efficiently.

But what if, as sometimes happens, your DB admin team further tightens the screws by  reducing spool space, or imposing new execution time or CPU usage limits? Then, you’ll have to go further to make queries efficient, as happened on one team that I was a part of. Beyond the steps previously recommended, here’s what we did: Continue reading →

How to be a good client

Leave a reply


I recently listened to Brian O’Neill’s excellent interview with Tom Davenport, headlined “Why on a scale of 1-10, the field of analytics has only gone from a one to about a two in ten years time.”

The conversation covered a lot of ground as Mr O’Neill and Mr Davenport explored the reasons why. Highlights included general lack of technical literacy and lack of an organizational data driven culture. But to their credit, they took responsibility on behalf of analytics professionals, emphasizing how we in the field could change in order to make more analytics efforts successful. Rather than focusing on providing technology-centered solutions, they recommended that data and AI professionals seek first to understand and empathize with their clients or internal customers, enabling data and AI pros to develop more effective analytics capabilities in light of that understanding.

I agree that analytics professionals can improve their game. However, as a former consultant who’s switched over to the client side, I think there’s room for improvement all around. To me, clients who work proactively to prepare for an analytics project position themselves for better outcomes. Continue reading →

Toward a Values-Based Approach to Auditing Agile Projects

Leave a reply

By now Agile has taken over waterfall as the dominant app dev project pattern*. In many large organizations, the traditional waterfall PMO also owns Agile projects. One aspect of PMO oversight that can work against Agile culture is the project audit. If the goal of an audit is to ensure the project reflects Agile values, it can help ensure working software and a satisfied customer. If not, an Agile project audit can reinforce process, documentation, and other values that don’t directly promote project success.

In this post I’ll briefly review the Agile Manifesto, recount some prominent advice for auditors of Agile projects, and offer suggestions for auditors who want to reinforce rather than suppress Agile values. Continue reading →

Leader’s Data Manifesto at #EDW19: Building a Foundation for Data Science

Leave a reply

It’s been a truism that data is a resource, but to prove it you just have to follow the money. As the illustration shows, the vast majority of corporate market value draws from intangible assets. Just as money is an abstraction that represents wealth, data is an abstraction that represents these intangible assets.

It’s year three after initial rollout of the Leader’s Data Manifesto (LDM). Since then, many widely publicized events have highlighted the value of data and metadata, and the importance of sound data management (here, here, and here). Recently at Enterprise Data World, John Ladley, Danette McGilvray, James Price, and Tom Redman presented this year’s LDM update. They reintroduced the Manifesto, recounted events of the past year, discussed strategy for the coming year, and issued a call to action for data professionals. Continue reading →

Toward an Analytics Code of Ethics

Leave a reply

In data management and analytics, we often focus on correcting apparent inability and unwillingness on the part of business leaders to effectively gather and capitalize on data resources. With that perspective, we often see ethics as a side issue difficult to prioritize given the scale and persistence of our other challenges.

At least that was my perspective, and my initial response when confronted recently by a family member on this topic. Her view from outside the field was that ethics should be a primary concern. As I’ve reflected on this conversation, I’ve come around to her point.

In recent years we’ve seen many examples of data misuse due to ethical lapses. Here’s a post that gives five examples, including police officers looking up data on individuals not related to any police business, an employee passing personal data including SSNs to a text sharing site, and Uber’s “god view”, available at the corporate level, which an employee used in 2014 to track a journalist’s location. Continue reading →

Sound Data Culture Enables Modern Data Architectures

Leave a reply

Modern data architectures, by enabling data analytics insights, promise to drive order of magnitude value gains across many business sectors (here, here, and here). Not so long ago, big data presented a daunting challenge. Although tools were plentiful, we struggled to conceptualize the architecture and organization within which to capitalize on those tools. Now solid frameworks have emerged. This post reviews two promising models for modern data architecture, and discusses two key cultural values critical to their successful adoption: drive to solve business challenges and drive for universal data correctness. Continue reading →

Leader’s Data Manifesto Annual Review: “It’s About the Lopez Women”

1 Reply

A year ago I recounted proceedings from the 2017 EDW World conference, which included release of the Leader’s Data Manifesto (LDM). Last week’s EDW World 2018 served as a one-year status report on the Manifesto. The verdict: there’s still a long way to go, but speakers and attendees report dramatic progress and emergence of shared values supporting data management’s role in enabling success and reducing risk.

To me the most compelling example of progress was the story of the Lopez women, told by Tommie Lawrence, who leads patient data quality efforts at Sharp Healthcare, a major San Diego, Ca, healthcare network. Ms. Lawrence’s team is responsible for data quality related to about six million patient records in the 40 highest priority of Sharp’s ~400 systems containing Patient Health Information (PHI).

A few years ago, Sharp Healthcare had two patients named Maria Lopez*, with birthdays one day apart. One suffered from kidney disease, the other had cancer. After a long wait a kidney was found, and the hospital called the Maria with kidney disease and asked her to come to the hospital for a transplant immediately. During operation prep, an assistant noticed that Maria had cancer, and put a halt to proceedings – it didn’t make sense to give the kidney to someone with cancer. Continue reading →