Integrating open source tools into a data warehouse has its advantages.
Although next-gen big data tools such as Hadoop, Spark, and MongoDB are finding more and more uses, most organizations need to maintain data in traditional relational stores as well. Deriving the benefits of both key/value stores and relational databases takes a lot of juggling. Three basic strategies are currently in use.
- Double up on your data storage. Log everything in your fast key/value repository and duplicate part of it (or perform some reductions and store the results) in your relational data warehouse.
- Store data primarily in a relational data warehouse, and use extract, transform, and load (ETL) tools to make it available for analytics. These tools run a fine-toothed comb through data to perform string manipulation, remove outlier values, etc. and produce a data set in the format required by data processing tools.
- Put each type of data into the repository best suited to it––relational, Hadoop, etc.––but run queries between the repositories and return results from one repository to another for post-processing.
The appeal of the first is a large-scale simplicity, in that it uses well-understood systems in parallel. The second brings the familiarity of relational databases for business users to access. This article focuses on the third solution, which has advantages over the others: it avoids the redundancy of the first solution and is much easier to design and maintain than the second. I’ll describe how it is accomplished by Teradata, through its appliances and cloud solutions, but the building blocks are standard, open source tools such as Hive and HCatalog, so this strategy can be implemented by anyone. Read more…
Cleaning and combining fields can turn messy data into actionable insight.
We often talk in business and computing about moving from “raw data” to “knowledge,” hoping to take useful actions based on the data our organization has collected over time. Before one can view trends in your data or do other analytics, you need tools for data cleaning and for combining multiple data sources into meaningful collections of information, known as entities. An entity may be a customer, a product, a point of sale, an incident being investigated by the police, or anything else around which you want to build meaningful context.
In this post, we’ll explore some of the complexities in real-life data that create headaches — and how analytical software can help users prepare data for sophisticated queries and visualizations. Read more…
Analytics can make combining or comparing data faster and less painful.
Entity resolution refers to processes that businesses and other organizations have to do all the time in order to produce full reports on people, organizations, or events. Entity resolution can be used, for instance, to:
- Combine your customer data with a list purchased from a data broker. Identical data may be in columns of different names, such as “last” and “surname.” Connecting columns from different databases is a common extract, transform, and load (ETL) task.
- Extract values from one database and match them against one or more columns in another. For instance, if you get a party list, you might want to find your clients among the attendees. A police detective might want to extract the names of people involved in a crime report and see whether any suspects are among them.
- Find a match in dirty data, such as a person whose name is spelled differently in different rows.
Dirty, inconsistent, or unstructured data is the chief challenge in entity resolution. Jenn Reed, director of product management for Novetta Entity Analytics, points out that it’s easy for two numbers to get switched, such as a person’s driver’s license and social security numbers. Over time, sophisticated rules have been created to compare data, and it often requires the comparison of several fields to make sure a match is correct. (For instance, health information exchanges use up to 17 different types of data to make sure the Marcia Marquez who just got admitted to the ER is the same Marcia Marquez who visited her doctor last week.) Read more…
Examples of multi-layer, three-tier data-processing architecture.
Like CPU caches, which tend to be arranged in multiple levels, modern organizations direct their data into different data stores under the principle that a small amount is needed for real-time decisions and the rest for long-range business decisions. This article looks at options for data storage, focusing on one that’s particularly appropriate for the “fast data” scenario described in a recent O’Reilly report.
Many organizations deal with data on at least three levels:
- They need data at their fingertips, rather like a reference book you leave on your desk. Organizations use such data for things like determining which ad to display on a web page, what kind of deal to offer a visitor to their website, or what email message to suppress as spam. They store such data in memory, often in key/value stores that allow fast lookups. Flash is a second layer (slower than memory, but much cheaper), as I described in a recent article. John Piekos, vice president of engineering at VoltDB, which makes an in-memory database, says that this type of data storage is used in situations where delays of just 20 or 30 milliseconds mean lost business.
- For business intelligence, theses organizations use a traditional relational database or a more modern “big data” tool such as Hadoop or Spark. Although the use of a relational database for background processing is generally called online analytic processing (OLAP), it is nowhere near as online as the previous data used over a period of just milliseconds for real-time decisions.
- Some data is archived with no immediate use in mind. It can be compressed and perhaps even stored on magnetic tape.
For the new fast data tier, where performance is critical, techniques such as materialized views further improve responsiveness. According to Piekos, materialized views bypass a certain amount of database processing to cut milliseconds off of queries. Read more…
Predixion service could signal a trend for smaller health facilities.
Analytics are expensive and labor intensive; we need them to be routine and ubiquitous. I complained earlier this year that analytics are hard for health care providers to muster because there’s a shortage of analysts and because every data-driven decision takes huge expertise.
Currently, only major health care institutions such as Geisinger, the Mayo Clinic, and Kaiser Permanente incorporate analytics into day-to-day decisions. Research facilities employ analytics teams for clinical research, but perhaps not so much for day-to-day operations. Large health care providers can afford departments of analysts, but most facilities — including those forming accountable care organizations — cannot.
Imagine that you are running a large hospital and are awake nights worrying about the Medicare penalty for readmitting patients within 30 days of their discharge. Now imagine you have access to analytics that can identify about 40 measures that combine to predict a readmission, and a convenient interface is available to tell clinicians in a simple way which patients are most at risk of readmission. Better still, the interface suggests specific interventions to reduce readmissions risk: giving the patient a 30-day supply of medication, arranging transportation to rehab appointments, etc. Read more…
A new report describes an imminent shift in real-time applications and the data architecture they require.
The era is here: we’re starting to see computers making decisions that people used to make, through a combination of historical and real-time data. These streams of data come together in applications that answer questions like:
- What news items or ads is this website visitor likely to be interested in?
- Is current network traffic part of a Distributed Denial of Service attack?
- Should our banking site offer a visitor a special deal on a mortgage, based on her credit history?
- What promotion will entice this gamer to stay on our site longer?
- Is a particular part of the assembly line overheating and need to be shut down?
Such decisions require the real-time collection of data from the particular user or device, along with others in the environment, and often need to be done on a per-person or per-event basis. For instance, leaderboarding (determining who is top candidate among a group of users, based on some criteria) requires a database that tracks all the relevant users. Such a database nowadays often resides in memory. Read more…
Still reflects conventions going back to original adoption of Objective-C
Like many Apple programmers (and new programmers who are curious about iOS), I treated Apple’s Swift language as a breath of fresh air. I welcomed when Vandad Nahavandipoor updated his persistently popular iOS Programming Cookbook to cover Swift exclusively. But I soon realized that the LLVM compiler and iOS runtime have persistent attributes of their own that have not gone away when programmers adopt Swift. This post tries to alert new iOS programmers to the idiosyncrasies of the runtime that they still need to learn.