Thursday, February 19, 2015

Data Warehouse in the times of Unstructured Data

We as humans find it easy to understand something when it is represented in a logical manner. On the other hand, computers and other machines need data to be organized in a structured manner to understand it. Structured relational data is the data represented in a structured way according to some specific rules that make it easy to understand, analyze and interpret. On the other hand, unstructured data refers to information without a predefined structure (obvious… isn’t it?). Computers don’t care if the data is logical or not. All they need is for the data to be organized in a particular manner. On the other hand, we humans can understand unorganized data like text, images, videos etc. Now-a-days, there are technologies with the capability to work on unstructured data. This has opened up new avenues for mankind as data previously considered unusable for computers can now be used. We can gleam new insights from it.

For structured data, languages like SQL are used to retrieve data. As we can guess, SQL presumes that the data is arranged in a structured manner. The statements used to retrieve data from database using SQL have a specific format (known as syntax). Although there are other languages/tools that are used to retrieve data from structured relational tables using common language phrases/sentences like fetch me X, Y and Z from table t1 where condition c1 happens, they internally rely on the data being structured.  

Talking about space requirements, structured relational data requires very little space as compared to unstructured data as structured data is designed to be used by machines. But, there have been 2 major changes in technology today that tilt the balance in favor of unstructured data: technologies to analyze unstructured data AND cheap storage. Owing to organization within a structure, structured data is easy to work with – for manual queries as well as automated queries (like search engines). But trying to understand unstructured data requires more than just a few queries. It requires one of the new functions of Web 3.0 – NLP (Natural language processing) which is a whole new game altogether. Examples of structure data include tables and spreadsheets. Examples of unstructured data are sensory data, call records data, images etc.

For most of the organizations, technology plays a supporting role. It is useful only if it can help the business gain strategic advantage over their peers. The technology to manage/analyze unstructured data came into place just a few years back. That is why, we now see organizations starting to adopt such technologies. Just looking at the volume of different types of data with organizations today:

Here, block based capacity refers to Structured data and file-based capacity refers to unstructured data


Technically speaking, a data warehouse is a system used for reporting and data analysis. They are centralized collection of integrated sources from variety of disparate sources. Traditionally, data warehouses were designed to work only with structured data. The sources of data as well as the methods used to work on them were based on the assumption that the data is structured. But now, the situation is different. Approximately 80% of business data is unstructured. And as expected, most of this 80% does not reside in a standard relational database. Businesses want to be able to rapidly analyze unstructured and structured data. Trying to store huge volume of unstructured data inside the traditional warehouse is a very tedious and time-consuming job.


If organizations want to deal with unstructured data, they either need to redesign their database from scratch, or they need to upgrade the existing databases and tools. They may have to start using/customizing big data tools and technologies like Hadoop and MapReduce. Although it is the matter of technology upgrade, the decision affects the organizations in critical ways. Hence, the decision has to involve business teams as well as technology teams. They have to incorporate integration techniques for all the processes from ETL to advanced analytics. They need to add metadata details for the unstructured data and that, is a very tedious process. Also care needs to be taken to avoid creating a data junkyard. New processes and systems for managing the documents has to be put in place. Techniques like the backward pointers might have to be used. Below is an example of how text analysis might be used



As fancy as it may sound, a data warehouse is not an elixir that could solve all the problems. There are some issues with analyzing data from a data warehouse      
  • Structured data is easy to manage in terms of ownership, security and privacy. But it is difficult to do so for unstructured data.
  • Storage and reteival of unstructured data from a warehouse is very difficult and time consuming
  • The amount of storage required for unstructured data is far more than what is required for structured data. An indirect implication of this is more time required to clean, filter and transform the unstructured data

Talking about the future of data warehouse, I feel that the traditional data warehouse will be highly integrated with the unstructured data warehouse. The primary purpose of the data warehouse will be to handle unstructured data. There will be more complex tools to work on unstructured data and they would also be integrated with the data warehouse. One major drawback of data warehouses today is the lack of real time analytics. This might not be true in future. With the advent of real-time data processing softwares, it seems plausible that the data warehouses in future would provide real time functionalities. Also, it is safe to assume that the data warehouse might be stored on clouds instead of traditional storage houses. Optimized warehouse is another thing that we can expect in future. Current warehouses are designed to work on static data. With unstructured data being stored in the database and the possibility of real-time analytics, we can expect future data warehouses to be highly optimized - for storage as well as for speed.

Overall, I feel that the data warehouse industry is poised to grow a lot and will go through a lot of changes in future. It will be a future that we all would like…


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