Tag Archive | data management

Data Quality, Data Maintenance

20121009 DataMaintenance

I read an interesting tidbit about data the other day:  the United States Postal Service processed more than 47 million changes of addresses in the last year.  That’s nearly 1 in 6 people. In the world of data, that factoid is a simple example of the challenge of addressing stale data and data quality.  The idea of stale data is that as data ages, its accuracy and associated business rules can change.

There’s lots of examples of how data in your data warehouse can age and degrade in accuracy and quality:  people move, area codes change, postal/zip codes change, product descriptions change, and even product SKUs can change.  Data isn’t clean and accurate forever; it requires constant review and maintenance. This shouldn’t be much of a surprise for folks that view data as a corporate asset; any asset requires ongoing maintenance in order to retain and ensure its value.  The challenge with maintaining any asset is establishing a reasonable maintenance plan.

Unfortunately, while IT teams are exceptionally strong in planning and carrying out application maintenance, it’s quite rare that data maintenance gets any attention.  In the data warehousing world, data maintenance is typically handled in a reactive, project-centric manner.  Nearly every data warehouse (or reporting) team has to deal with data maintenance issues whenever a company changes major business processes or modifies customer or product groupings (e.g. new sales territories, new product categories, etc.)  This happens so often, most data warehouse folks have even given it a name:  Recasting History.   Regardless of what you call it, it’s a common occurrence and there are steps that can be taken to simplify the ongoing effort of data maintenance.

  • Establish a regularly scheduled data maintenance window.  Just like the application maintenance world, identify a window of time when data maintenance can be applied without impacting application processing or end user access
  • Collect and publish data quality details.  Profile and track the content of the major subject area tables within your data warehouse environment. Any significant shift in domain values, relationship details, or data demographics can be discovered prior to a user calling to report an undetected data problem
  • Keep the original data.  Most data quality processing overwrites original content with new details.  Instead, keep the cleansed data and place the original values at the end of your table records. While this may require a bit more storage, it will dramatically simplify maintenance when rule changes occur in the future
  • Add source system identification and creation date/time details to every record.  While this may seem tedious and unnecessary, these two fields can dramatically simplify maintenance and trouble shooting in the future
  • Schedule a regular data change control meeting.  This too is similar in concept to the change control meeting associated with IT operations teams.  This is a forum for discussing data content issues and changes

Unfortunately, I often find that data maintenance is completely ignored. The problem is that fixing broken or inaccurate data isn’t sexy; developing a data maintenance plan isn’t always fun.   Most data warehouse development teams are buried with building new reports, loading new data, or supporting the ongoing ETL jobs; they haven’t given any attention to the quality or accuracy of the actual content they’re moving and reporting.   They simply don’t have the resources or time to address data maintenance as a proactive activity.

Business users clamor for new data and new reports; new funding is always tied to new business capabilities.  Support costs are budgeted, but they’re focused on software and hardware maintenance activities.  No one ever considers data maintenance; it’s simply ignored and forgotten.

Interesting that we view data as a corporate asset – a strategic corporate asset – and there’s universal agreement that hardware and software are simply tools to support enablement.  And where are we investing in maintenance?  The commodity tools, not the strategic corporate asset.

Photo courtesy of DesignzillasFlickr via Flickr (Creative Commons license).

Advertisements

Advanced Data Virtualization Capabilities

20130925 AdvancedDV

In one of my previous blogs, I wrote about Data Virtualization technology — one of the more interesting pieces of middleware technology that can simplify data management.   While most of the commercial products in this space share a common set of features and functions, I thought I’d devote this blog to discussing the more advanced features.  There are quite a few competing products; the real challenge in differentiating the products is to understand their more advanced features.

The attraction of data virtualization is that it simplifies data access.  Most IT shops have one of everything – and this includes several different brands of commercial DBMSs, a few open source databases, a slew of BI/reporting tools, and the inevitable list of emerging and specialized tools and technologies (Hadoop, Dremel, Casandra, etc.) Supporting all of the client-to-server-to-repository interfaces (and the associated configurations) is both complex and time consuming.  This is why the advanced capabilities of Data Virtualization have become so valuable to the IT world.

The following details aren’t arranged in any particular order.  I’ve identified the ones that I’ve found to be the most valuable (and interesting).  Let me also acknowledge not every DV product supports all of these features.

Intelligent data caching.  Repository-to-DV Server data movement is the biggest obstacle in query response time.  Most DV products are able to support static caching to reduce repetitive data movement (data is copied and persisted in the DV Server).  Unfortunately, this approach has limited success when there are ad hoc users accessing dozens of sources and thousands of tables.  The more effective solution is for the DV Server to monitor all queries and dynamically cache data based on user access, query load, and table (and data) access frequency.

Query optimization (w/multi-platform execution). While all DV products claim some amount of query optimization, it’s important to know the details. There are lots of tricks and techniques; however, look for optimization that understands source data volumes, data distribution, data movement latency, and is able to process data on any source platform.

Support for multiple client Interfaces.  Since most companies have multiple database products, it can be cumbersome to support and maintain multiple client access configurations.  The DV server can act as a single access point for multiple vendor products (a single ODBC interface can replace drivers for each DBMS brand).  Additionally, most DV Server drivers support multiple different access methods (ODBC, JDBC, XML, and web services).

Attribute level or value specific data security.  This feature supports data security at a much lower granularity than is typically available with most DBMS products.  Data can be protected (or restricted) at individual column values for entire table or selective rows.

Metadata tracking and management.  Since Data Virtualization is a query-centric middleware environment, it only makes sense to position this server to retrieve, reconcile, and store metadata content from multiple, disparate data repositories.

Data lineage. This item works in tandem with the metadata capability and augments the information by retaining the source details for all data that is retrieved.  This not only includes source id information for individual records but also the origin, creation date, and native attribute details.

Query tracking for usage audit. Because the DV Server can act as a centralized access point for user tool access, there are several DV products that support the capture and tracking of all submitted queries.  This can be used to track, measure, and analyze end user (or repository) access.

Workflow linkage and processing.  This is the ability to execute predefined logic against specific data that is retrieved. While this concept is similar to a macro or stored procedure, it’s much more sophisticated.  It could include the ability to direct job control or specialized processing against an answer set prior to delivery (e.g. data hygiene, external access control, stewardship approval, etc.)

Packaged Application Templates.  Most packaged applications (CRM, ERP, etc.) contain thousands of tables and columns that can be very difficult to understand and query.  Several DV vendors have developed templates containing predefined DV server views that access the most commonly queried data elements.

Setup and Configuration Wizards. Configuring a DV server to access the multiple data sources can be a very time consuming exercise; the administrator needs to define and configure every source repository, the underlying tables (or files), along with the individual data fields.  To simplify setup, a configuration wizard reviews the dictionary of an available data source and generates the necessary DV Server configuration details. It further analyzes the table and column names to simplify naming conventions, joins, and data value conversion and standardization details.

Don’t be misled into thinking that Data Virtualization is a highly mature product space where all of the products are nearly identical.  They aren’t.  Most product vendors spend more time discussing their unique features instead of offering metrics about their their core features.  It’s important to remember that every Data Virtualization product requires a server that retrieves and processes data to fulfill query requests. This technology is not a commodity, which means that details like setup/configuration time, query performance, and advanced features can vary dramatically across products.  Benchmark and test drive the technology before buying.

The Power of Data Virtualization

20130911 Doorway

I was participating in a discussion about Data Virtualization (DV) the other day and was intrigued with the different views that everyone had about a technology that’s been around for more than 10 years. For those of you that don’t participate in IT-centric, geekfest discussions on a regular basis, Data Virtualization software is middleware that allows various disparate data sources to look like a single relational database.  Some folks characterize Data Virtualization as a software abstraction layer that removes the storage location and format complexities associated with manipulating data. The bottom line is that Data Virtualization software can make a BI (or any SQL) tool see data as though it’s contained within a single database even though it may be spread across multiple databases, XML files, and even Hadoop systems.

What intrigued me about the conversation is that most of the folks had been introduced to Data Virtualization not as an infrastructure tool that simplifies specific disparate data problems, but as the secret sauce or silver bullet for a specific application. They had all inherited an application that had been built outside of IT to address a business problem that required data to be integrated from a multitude of sources.  And in each instance, the applications were able to capitalize on Data Virtualization as a more cost effective solution for integrating detailed data. Instead of building a new platform to store and process another copy of the data, they used Data Virtualization software to query and integrate data from the individual sources systems. And each “solution” utilized a different combination of functions and capabilities.

As with any technology discussion, there’s always someone that believes that their favorite technology is the best thing since sliced bread – and they want to apply their solution to every problem.  Data Virtualization is an incredibly powerful technology with a broad array of functions that enable multi-source query processing. Given the relative obscurity of this data management technology, I thought I’d review some of the more basic capabilities supported by this technology.

Multi-Source Query Processing.  This is often referred to as Query Federation. The ability to have a single query process data across multiple data stores.

Simplify Data Access and Navigation.  Exposes data as single (virtual) data source from numerous component sources. The DV system handles the various network, SQL dialect, and/or data conversion issues.

Integrate Data “On the Fly”.  This is referred to as Data Federation. The DV server retrieves and integrates source data to support each individual query. 

Access to Non-Relational Data. The DV server is able to portray non-relational data (e.g. XML data, flat files, Hadoop, etc.) as structured, relational tables.  

Standardize and Transform Data. Once the data is retrieved from the origin, the DV server will convert the data (if necessary) into a format to support matching and integration.

Integrate Relational and Non-Relational Data. Because DV can make any data source (well, almost any) look like a relational table, this capability is implicit. Keep in mind that the data (or a subset of it) must have some sort of implicit structure.  

Expose a Data Services Interface. Exposing a web service that is attached to a predefined query that can be processed by the DV server.

Govern Ad Hoc Queries. The DV Server can monitor query submissions, run time, and even complexity – and terminate or prevent processing under specific rule-based situations.

Improve Data Security.  As a common point of access, the DV Server can support another level of data access security to address the likely inconsistencies that exist across multiple data store environments.

As many folks have learned, Data Virtualization is not a substitute for a data warehouse or a data mart.  In order for a DV Server to process data, the data must be retrieved from the origin; consequently, running a query that joins tables spread across multiple systems containing millions of records isn’t practical.  An Ethernet network is no substitute for the high speed interconnect linking a computer’s processor and memory to online storage. However, when the data is spread across multiple systems and there’s no other query alternative, Data Virtualization is certainly worth investigating.

Project Success = Data Usability

One of the challenges in delivering successful data-centric projects (e.g. analytics, BI, or reporting) is realizing that the definition of project success differs from traditional IT application projects.  Success for a traditional application (or operational) project is often described in terms of transaction volumes, functional capabilities, processing conformance, and response time; data project success is often described in terms of business process analysis, decision enablement, or business situation measurement.  To a business user, the success of a data-centric project is simple: data usability.

It seems that most folks respond to data usability issues by gravitating towards a discussion about data accuracy or data quality; I actually think the more appropriate discussion is data knowledge.  I don’t think anyone would argue that to make data-enabled decisions, you need to have knowledge about the underlying data.  The challenge is understanding what level of knowledge is necessary.  If you ask a BI or Data Warehouse person, their answer almost always includes metadata, data lineage, and a data dictionary.  If you ask a data mining person, they often just want specific attributes and their descriptions — they don’t care about anything else.  All of these folks have different views of data usability and varying levels (and needs) for data knowledge.

One way to improve data usability is to target and differentiate the user audience based on their data knowledge needs.  There are certainly lots of different approaches to categorizing users; in fact, every analyst firm and vendor has their own model to describe different audience segments.  One of the problems with these types of models is that they tend to focus heavily on the tools or analytical methods (canned reports, drill down, etc.) and ignore the details of data content and complexity. The knowledge required to manipulate a single subject area (revenue or customer or usage) is significantly less than the skills required to manipulate data across 3 subject areas (revenue, customer, and usage).  And what exacerbates data knowledge growth is the inevitable plethora of value gaps, inaccuracies, and inconsistencies associated with the data. Data knowledge isn’t just limited to understanding the data; it includes understanding how to work around all of the imperfections.

Here’s a model that categories and describes business users based on their views of data usability and their data knowledge needs

Level 1: “Can you explain these numbers to me?”

This person is the casual data user. They have access to a zillion reports that have been identified by their predecessors and they focus their effort on acting on the numbers they get. They’re not a data analyst – their focus is to understand the meaning of the details so they can do their job. They assume that the data has been checked, rechecked, and vetted by lots of folks in advance of their receiving the content. They believe the numbers and they act on what they see.

Level 2: “Give me the details”

This person has been using canned reports, understands all the basic details, and has graduated to using data to answer new questions that weren’t identified by their predecessors.  They need detailed data and they want to reorganize the details to suit their specific needs (“I don’t want weekly revenue breakdowns – I want to compare weekday revenue to weekend revenue”).  They realize the data is imperfect (and in most instances, they’ll live with it).  They want the detail.

Level 3: “I don’t believe the data — please fix it”

These folks know their area of the business inside/out and they know the data. They scour and review the details to diagnose the business problems they’re analyzing.  And when they find a data mistake or inaccuracy, they aren’t shy about raising their hand. Whether they’re a data analyst that uses SQL or a statistician with their favorite advanced analytics algorithms, they focus on identifying business anomalies.  These folks are the power users that are incredibly valuable and often the most difficult for IT to please.

Level 4: “Give me more data”

This is subject area graduation.  At this point, the user has become self-sufficient with their data and needs more content to address a new or more complex set of business analysis needs. Asking for more data – whether a new source or more detail – indicates that the person has exhausted their options in using the data they have available.  When someone has the capacity to learn a new subject area or take on more detailed content, they’re illustrating a higher level of data knowledge.

One thing to consider about the above model is that a user will have varying data knowledge based on the individual subject area.  A marketing person may be completely self-sufficient on revenue data but be a newbie with usage details.  A customer support person may be an expert on customer data but only have limited knowledge of product data.  You wouldn’t expect many folks (outside of IT) to be experts on all of the existing data subject areas. Their knowledge is going to reflect the breadth of their job responsibilities.

As someone grows and evolves in business expertise and influence, it’s only natural that their business information needs would grow and evolve too.  In order to address data usability (and project success), maybe it makes sense to reconsider the various user audience categories and how they are defined.  Growing data knowledge isn’t about making everyone data gurus; it’s about enabling staff members to become self-sufficient in their use of corporate data to do their jobs.

Photo “Ladder of Knowledge” courtesy of degreezero2000 via Flickr (Creative Commons license).

The Formula for Analytics Success: Data Knowledge


Companies spend a small fortune continually investing and reinvesting in making their business analysts self-sufficient with the latest and greatest analytical tools. Most companies have multiple project teams focused on delivering tools to simplify and improve business decision making. There are likely several standard tools deployed to support the various data analysis functions required across the enterprise: canned/batch reports, desktop ad hoc data analysis, and advanced analytics. There’s never a shortage of new and improved tools that guarantee simplified data exploration, quick response time, and greater data visualization options, Projects inevitably include the creation of dozens of prebuilt screens along with a training workshop to ensure that the users understand all of the new whiz bang features associated with the latest analytic tool incarnation.  Unfortunately, the biggest challenge within any project isn’t getting users to master the various analytical functions; it’s ensuring the users understand the underlying data they’re analyzing.

If you take a look at the most prevalent issue with the adoption of a new business analysis tool is the users’ knowledge of the underlying data.  This issue becomes visible with a number of common problems:  the misuse of report data, the misunderstanding of business terminology, and/or the exaggeration of inaccurate data.  Once the credibility or usability of the data comes under scrutiny, the project typically goes into “red alert” and requires immediate attention. If ignored, the business tool quickly becomes shelfware because no one is willing to take a chance on making business decisions based on risky information.

All too often the focus on end user training is tool training, not data training. What typically happens is that an analyst is introduced to the company’s standard analytics tool through a “drink from a fire hose” training workshop.  All of the examples use generic sales or HR data to illustrate the tool’s strengths in folding, spindling, and manipulating the data.  And this is where the problem begins:  the vendor’s workshop data is perfect.  There’s no missing or inaccurate data and all of the data is clearly labeled and defined; classes run smoothly, but it just isn’t reality  Somehow the person with no hands-on data experience is supposed to figure out how to use their own (imperfect) data. It’s like someone taking their first ski lesson on a cleanly groomed beginner hill and then taking them up to the top of an a black diamond (advanced) run with step hills and moguls.  The person works hard but isn’t equipped to deal with the challenges of the real world.  So, they give up on the tool and tell others that the solution isn’t usable.

All of the advanced tools and manipulation capabilities don’t do any good if the users don’t understand the data. There are lots of approaches to educating users on data.  Some prefer to take a bottom-up approach (reviewing individual table and column names, meanings, and values) while others want to take a top-down approach (reviewing subject area details, the associated reports, and then getting into the data details).  There are certainly benefits of one approach over the other (depending on your audience); however, it’s important not to lose sight of the ultimate goal: giving the users the fundamental data knowledge they need to make decisions.  The fundamentals that most users need to understand their data include a review of

The above details may seem a bit overwhelming if you consider that most companies have mature reporting environments and multi-terabyte data warehouses.  However, we’re not talking about training someone to be an expert on 1000 data attributes contained within your data warehouse; we’re talking about ensuring someone’s ability to use an initial set of reports or a new tool without requiring 1-on-1 training.  It’s important to realize that the folks with the greatest need for support and data knowledge are the newbies, not the experienced folks.

There are lots of options for imparting data knowledge to business users:  a hands-on data workshop, a set of screen videos showing data usage examples, or a simple set of web pages containing definitions, textual descriptions, and screen shots. Don’t get wrapped up in the complexities of creating the perfect solution – keep it simple.  I worked with a client that deployed their information using a set of pages constructed with PowerPoint that folks could reference in a the company’s intranet. If your users have nothing – don’t’ worry about the perfect solution – give them something to start with that’s easy to use.

Remember that the goal is to build users’ data knowledge that is sufficient to get them to adopt and use the company’s analysis tools.  We’re not attempting to convert everyone into data scientists; we just want them to use the tools without requiring 1-on-1 training to explain every report or data element.

Photo courtesy of NASA.  Nasa Ames Research Center engineer H Julian “Harvey” Allen illustrating data knowledge (relating to capsule design for the Mercury program)

Data Governance: Managing Data as an Asset

 

20121029 GoldBullionI always find it interesting when people pile onto the company’s latest and most popular project or initiative. People love to gravitate to whatever is new and sexy within the company, regardless of what they’re working on or their current responsibilities. There never seems to be a shortage of the “bright shiny object” syndrome – you know, organizational ADHD.  This desire to jump on the band wagon often positions individuals with limited experience to own and drive activities they don’t fully understand. The world of data governance is rife with supporters and promoters that are thrilled to be involved, but a bit unprepared to participate and execute.  It’s like loading a gun and pulling the trigger before aiming – you’ll make a lot of noise and likely miss the target.  If only folks spent a bit of time educating others about the meaning and purpose of data governance before they got started.

Let me first offer up some definitions from a few reputable sources…

“Data governance is a set of processes that ensures that important data assets are formally managed throughout the enterprise” (Wikipedia)

“The process by which an organization formalizes the ‘fiduciary duty’ for the management of data assets”  (Forrester Research)

 “…the overall management of the availability, usability, integrity, and security of the data employed in an enterprise” (TechTarget)

For those of you that have experience with data governance, the above definitions are unlikely to be much of a surprise.  For the other 99%, there’s likely to be some head scratching. I actually think most folks that haven’t been indoctrinated to the religion of data have just assumed that data governance is simply a new incarnation of yesterday’s data quality or metadata discussion.  That probably shouldn’t be much of a surprise; the discussion of data inaccuracy and data dictionaries has gotten so much air time over the past 30 years, the typical business user probably feels brainwashed when they hear anything with “data” in the title.  I actually think that Data Governance may win the prize for being among the most misunderstood concepts within Information Technology.

Data governance is a very simple concept.  Data Governance is about establishing the processes for accessing and sharing data and resolving conflict when the processes don’t work.

A Data Governance initiative is really about instilling the concept of managing data as a corporate asset. Companies have standard methods and processes for asset management: your Procurement group has a slew of rules and processes to support the purchasing of office supplies; the HR organization has rules and guidelines for hiring and managing staff; and the finance organization follows “generally accepted accounting principles” to handle managing the company’s fixed and financial assets.  Unfortunately, what we don’t have is a set of generally accepted principles for data. This is what data governance establishes.

The reason that you see the term process in nearly every definition of data governance is that until you establish and standardize data related processes, you’ll never get any of the work done. Getting started with data governance isn’t about establishing a committee – it’s about identifying the goals and identifying the policies and processes that will direct the work activities. You can’t be successful in managing an asset if everyone has their own rules and methods for accessing, manipulating, and using the asset.  This isn’t rocket science – geez – the world of ERP implementations and even business reengineering projects learned this concept more than 10 years ago.

The reason to manage data as a corporate asset is to ensure that business activities that require data are able to use and access data in a simple, uniform, consistent manner.  Unfortunately, in the era of search engines, content indexing, data warehouses, and the Cloud,  finding and acquiring data to support a new business need can be painful, time consuming, and expensive.  Everyone has their own terms, their own private data stash, and their own rules dictating who is and isn’t allowed to access data.  This isn’t corporate asset management– this is corporate asset chaos.  A data governance initiative is one of the best ways to get started in managing data as a corporate asset.

The Flaw of the Data Inventory

Grecian Urn 2

Back when I was applying to college, I’d read over college catalogs. Inevitably, each university would mention the number of books it had in its library. When I finally went to college, I realized that this metric was fairly meaningless. A dozen volumes on Grecian pottery did me no good when I was in search of a book on polymers for my mechanical engineering class.

Clients will often ask us to scope a “data inventory” project, inevitably focused on identifying and describing all the data elements contained across their different application systems. Recently a new CIO asked us to head up a “tiger team” to inventory his company’s data. He was surprised at the quantity of information needs that had been sent his way. As expected, he inquired about systems of record and data dictionaries. As you can imagine, he received multiple and conflicting answers which only exacerbated his confusion.

As a point of reference, well-known ERP systems can have in excess of 50,000 discrete data elements in their databases (never mind that some aren’t in English). As I’ve written in the past, many of these data elements have no use outside of the application itself.

Having terabyte upon terabyte of information is equally irrelevant if that data is unrelated to current business issues. The problem with a data inventory activity is that identifying and counting data elements in different systems and applications won’t necessarily solve any problems. Why? Because data across applications and packages is inconsistent: there are different names, definitions, and values, and there is no practical means of determining which data they actually have in common. This is like going to the hardware store and looking for a specific screw, but all the different screws are in one big barrel—you end up having to pick through each screw, one at time. When you find the screw, you just throw all the other screws back into the barrel.

The point of a data inventory isn’t to pick through data because it exists, but to inventory the data people actually need. If you’re going to undertake a data inventory, your output should be structured so that the next person doesn’t have to repeat your work.  Identify the data that is moving across various systems, as this indicates key information that’s being shared. Categorize this data by subject area. You’ll inevitably find that there are inconsistent versions of the data, enabling you to identify data disparities. You can then begin to develop a catalog of key corporate data that will form the basis of your data dictionary.

Inventorying the data that moves between systems accomplishes two things: it identifies the most valuable data elements in use, and it will also help identify data that’s not high-value, as it’s not being shared or used. This approach also provides a way to tackle initial data quality efforts by identifying the most “active” data used by the business. It ultimately helps the data management team understand where to focus its efforts, and prioritize accordingly.

So next time someone suggests a data inventory without context or objectives, consider sending them to college to study Grecian urns.

%d bloggers like this: