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White Papers

Browse our white papers to get a thorough grounding in big data issues; enabling technologies, including NoSQL and Apache Cassandra; business and technical benefits; solution descriptions and much more. Have an idea for a topic you’d like us to cover? Tell us about it. If you’re looking for more technical information, you’ll find it in our Developer Center.

Architect's Guide to NoSQL

Read this comprehensive guide to learn how all the key areas of database design, creation, security, object management, backup/recovery, monitoring and tuning, data migrations, and more - are carried out in a NoSQL database.  

Solving IoT Data Management Challenges

In this white paper, you’ll learn about the three most important issues surrounding data management in the age of IoT. You'll also learn how DataStax Enterprise, built on Apache Cassandra™ and native to hybrid cloud environments, is paving the way for the future of data management. Download the white paper to learn more now.  

The 5 Things Your Enterprise Needs to Manage IoT Data at Scale

In this ebook, you’ll learn about these five technologies and their benefits. To continue to develop and scale your IoT-driven applications, your infrastructure needs to be able to handle sensor data at velocity, keep data close to the edge, maintain 100% uptime, and make it easy to extract business value. The insights you’ll discover in this ebook will not only help you prepare your organization for this reality, they’ll help you take full advantage of IoT data.  

DataStax Enterprise on VMware vSAN™ 6.7 All-Flash for Production

All organizations are on a cloud journey, adopting a hybrid cloud or multi-cloud strategy, driven by the needs of their organization and customers. VMware and DataStax offer a multi-cloud solution that provides enterprise-grade, cross-cloud availability, multi-cloud operations, and intrinsic security enabling customers to build and deploy applications at scale with confidence.  

The Journey to Hybrid Cloud with DataStax Enterprise: 5 Keys to Success

Here it is - Hybrid and multi-cloud computing environments are evolving fast as more companies seek to combine the power of on-premises data centers with the advantages of large cloud service providers. This white paper discusses best practices for moving to a hybrid or multi-cloud environment and the role that DataStax can play in helping enterprises achieve success on their hybrid cloud journey.  

GovLoop Report - Powering Growth and Innovation for Hybrid Cloud

Federal agencies dealing with multiple facilities and sensitive data related to national and infrastructure security need to be two steps ahead of the game when it comes to data management. In that spirit, GovLoop has partnered with DataStax for this market trends report on how agencies can take full advantage of hybrid cloud.  

Four Key Technologies that Enable Microservices

Due to their ability to enable rapid application development and deployment and easy problem fixes, microservices are quickly becoming the key go-to strategy for quick and agile development of modern applications. This ebook describes the four technologies that enable microservices: Saga, Command Query Responsibility Segregation, hybrid cloud, and containerization.  

Apache Cassandra™ Architecture

Data management challenges have evolved drastically over the last decade, leading most companies to rethink how they manage their data. The need for more powerful and far more flexible databases resulted in the birth of the NoSQL database Apache Cassandra™. Read this white paper to learn how Cassandra has evolved and how it works.  

How DataStax Will Help You Comply With The New GDPR

There are certain things all enterprises need to know about how the European Union's General Data Protection Regulation will affect their data storage and handling. For CX leaders, bringing together the full potential of real-time data with all the necessary security and privacy considerations will be a delicate balancing act. These applications can’t be taken offline to deal with data deletion or audit requests, and they will have to function at scale. Read this data sheet to learn how DataStax can help your company's business-critical apps function highly at scale while still complying with the latest data regulations.  

Top 5 Data Challenges Facing Insurance Companies

Insurance companies have been collecting data for as long as they’ve been around in order to assess risk, set policy prices, and answer customer queries. Most times, however, the data is forgotten about after the policy is issued and is consigned to a dusty filing cabinet or ageing legacy database. This ebook outlines the data challenges facing insurance companies and how to avoid them.  

How to Save Millions on Legacy Mainframe Operations

Mainframe technology is struggling to keep up with the data demands of today’s businesses. And yet, many businesses continue to rely on mainframes in spite of growing concerns around security, capacity, and performance. This white paper explains how adopting a data modernization strategy that incorporates your mainframe can save you millions of dollars in operating costs.  

Mission Modernization with Active Everywhere Architectures

The operational needs of public agencies are evolving at a pace that’s almost impossible for legacy applications to keep up with. To survive, agencies need to take a new approach to data management: one that uses real-time analytics and always-on capabilities to power game-changing cloud applications.  

The Power of an Enterprise Data Layer

An enterprise data layer is the fabric that weaves together all the disparate data coming from your various cloud and/or on-premises data sources. This ebook explains how an enterprise data layer works and why it’s so important for deploying applications in multi- and hybrid cloud environments.  

The Power of an Active Everywhere Database

Active-active and active-passive were the traditional approaches to handling distributed data via multiple data centers. Now—a new approach has arrived, and it addresses the real pain points of enterprises struggling with hybrid and/or multi-cloud architectures and how best to deploy mission-critical applications across these environments: Active Everywhere.  

Optimizing Data Management in Containers With Kubernetes and DataStax

Containers and orchestration technologies have surged in popularity in the database world over the last few years. Today’s enterprise-grade applications practically require these technologies now, but there are certain challenges to making them work to their optimal potential. This white paper explains what those challenges are and how DataStax supports containers and Kubernetes.  

SQL Support in DataStax Enterprise

Learn about Structured Query Language (SQL) support in DataStax Enterprise, how Cassandra Query Language (CQL) was developed, and how Spark SQL is used with DSE Analytics.  

DataStax Customer Experience Benchmark Report

Companies across industries are having a tough time getting their customer experience engines running. Read this DataStax benchmark report for an overview of the issues they’re dealing with and the key technology concerns around crafting top-notch customer experience initiatives.  

The Architect’s Guide to Customer Experience

Architects need to know how to create great customer experiences from the data layer. But building a powerful customer experience platform that can create contextual, in-the-moment experiences at every touchpoint isn’t easy. From real-time analytics to scalability to data access and governance, this ebook provides the comprehensive picture of the elements that make up the modern-day customer experience data framework.  

Accelerate App Development by Harmonizing Your Legacy Databases

Today’s applications require always-on performance and easy scalability to adapt to the constantly shifting demands of the Right-Now Customer. This white paper explains why legacy technology such as relational databases don’t work for this, and why you actually shouldn’t have to replace this technology—just build on it with a distributed cloud database.  

Modernizing Mission-Critical Apps for Public Sector

The public sector is at a crossroads when it comes to data usage. Government agencies are facing new threats but also incredible new opportunities when it comes to unlocking the full potential of their data. Read this ebook to learn how applications aimed at the public sector can benefit from data layer transformation.  

DataStax for Omnichannel

Today’s enterprise-level omnichannel initiatives are about a lot more than just creating great buying experiences: they’re about the entire quote-to-cash lifecycle. Read this ebook for a clear look at how enterprises like Sony, eBay, Walmart, and Safeway use DataStax to power their ecommerce engines.  

How to Ensure Your eCommerce Applications are Always On at Scale

eCommerce applications are in higher demand than ever, but enterprises are still trying to figure out how to get them to perform seamlessly at scale. With the right database foundation, an ecommerce application can be made fast, highly personalized, and delightful. Read this white paper to learn how it happens.  

Why Financial Services and Banks Need An Operational Data Layer

Banking customers are more demanding and fickle than ever, and financial data has become both more valuable and and more vulnerable than ever. This ebook explains why having an easily scalable operational data layer built on a distributed cloud database is key for banks to survive in the Right-Now Economy.  

Evaluating Cloud Databases for eCommerce Applications

Cloud databases have evolved to support a variety of use cases, perhaps none more vital to the Right-Now Economy then ecommerce. Given the volume and variety of data pouring in, building great ecommerce applications is no simple feat. Read this ebook to learn why today’s ecommerce apps need an always-on cloud database.  

How Banking Fraud is Changing with Data and AI

The world of fraud and fraud protection are changing rapidly. This white paper delves into the problems of protecting against fraud via relational databases, and how artificial intelligence is key to proactively fending off today’s fraudsters.  

DataStax Enterprise Analytics

Right-Now Enterprises need powerful analytics to effectively do everything from customer 360, to fraud detection, to personalization and recommendations, to forecasting and modeling. This white paper explains how DataStax Enterprise (DSE) Analytics works, and the specific features it uses to perform cost-effective, real-time analytics at scale  

Operational Simplicity with DataStax Enterprise

Keeping things simple is key for today’s database administrators. The easier it is to manage your database, the more time you have to devote to the things you really love, like innovation and building amazing applications. Read this white paper to learn how DataStax Enterprise simplifies data management operations.  

Advanced Performance with DataStax Enterprise

DataStax Enterprise (DSE) 6 builds greatly on the performance of previous DSE versions, offering a whole new level of database power, flexibility, and analytics. This white paper explains the specific features, such as thread per core and asynchronous architecture, that make it an incredibly powerful distributed cloud database built for the Right-Now Enterprise.  

Designing a Distributed Cloud Database for Dummies

Real-time applications are unquestionably the way of the future, but many if not most enterprises are still struggling to meet the data requirements of the Right-Now Economy. This succinct, easy-to-understand guide explains the value of cloud databases and the specific capabilities that make cloud databases the perfect solution for providing powerful, real-time applications.  

The Way of Customer 360

Customer 360 is more than just “knowing the customer”—it’s integrating key data sources to produce real-time insights that create loyalty and genuine bonding with your brand and enterprise. This ebook explains why C360 is in fact a sort of art that demands five key characteristics from the way you integrate and store your data.  

Real-Time Data and Public Sector Modernization

Public sector investments in big data have skyrocketed over the last five years, and for good reason: big data can help enterprises deliver on certain key digital transformation promises. But public sector entities are overlooking real-time data at their own peril. This ebook explains the difference between big data and real-time data, and why you need both to thrive in the Right-Now Economy.  

DataStax for Enterprises

When your data layer is fast, nimble, flexible, and adaptable, your enterprise goes from being potentially disrupted to being a powerful disruptor. From customer 360 platforms to 100% uptime to game-changing customer experience applications, learn how some of our time’s most successful and innovative companies are using DataStax technology.  

Transform Your Digital Core Banking Experience

Banks are at an inflection point. Siloed data and legacy systems are no longer enough to satisfy today’s average banking customer, and digital disruption has made the banking industry unstable and dangerous, but also filled with opportunity. Read this ebook to learn exactly what today’s banking customers desire from their banking experiences, and why your data layer is so key to being able to provide these experiences.  

Transform Your Digital Omni-Channel Experience

Few industries have been more “touched” by the digital revolution than telecommunications. But most telecom companies are still failing to capitalize on this new digital telecom world because they’re not using the right tools and technology. Read this ebook to learn how telecommunication companies can transform their digital omnichannel experiences via the data layer.  

Becoming a Customer-Centric Organization

In today’s fast-paced business climate, the ability to handle big data and contextualize it in real time for actionable, loyalty-producing insights marks the difference between companies that thrive and those who don’t. Read this ebook to learn why using real-time data and a design thinking approach can help your organization successfully compete in today’s customer-centric economy.  

When a Fully Managed Data Platform is Right For You

When is it time to pull the trigger on a fully managed data management platform? What questions should you be asking of your enterprise to see if a fully managed data platform is right for you? From DBA empowerment to running your business-critical apps in the cloud, read this e-book to learn the advantages of a fully managed data platform and how you can assess if your enterprise is ready for one.  

Achieving Data Security and Compliance with DataStax Enterprise

Enterprises today face increasingly powerful security threats, exploding volumes of data, and ever more complex and cumbersome compliance requirements. These combined factors make the case for needing an extremely comprehensive but also very nimble data security solution. Read this white paper to learn how DataStax Enterprise (DSE) Advanced Security helps enterprises protect their data and meet compliance, and why DSE Advanced Security is second to none in its ability to do this.  

Banking Transformation With DataStax

Capital One, TCF, ING, Itaú, UBS, Macquarie, and NYSE – all use DataStax to handle their incredibly large and complex volumes of financial data in real time and to build powerful, applications that adapt in-the-moment to internal and external enterprise demands. Read this ebook for a revealing snapshot of each happy banking DataStax client and how they use our technology.  

Are Your Technology Decisions Killing Your Customer Experience?

Today’s customers expect quick, seamless, intelligent, personalized experiences at all times regardless of channel or location. To deliver these optimal customer experiences, you need a solid but nimble database architecture capable of scaling, flexing, and adapting in real time. Read this ebook to learn how your database technology decisions be the difference between transformational customer experiences that boost your bottom line or lackluster encounters that drive customers away.

The Database Platform for Cloud Applications

DataStax Enterprise 5.0 makes it easier to build and run large-scale, interactive and intelligent applications. Learn more about the robust multi-model capabilities (e.g. DSE Graph) and new features that will simplify and automate the management, monitoring and development tasks in DataStax Enterprise.  

The Untold Story of Apache Cassandra

Until now, it’s been a pretty well-kept secret that DataStax is the driving force behind Apache Cassandra, growing it from a passionate Facebook coding community into a database that powers more than 30 percent of the Fortune 100, including Netflix, Cisco and eBay. Download this ebook to learn how this happened, and how one dinner at a cheap Thai restaurant in Texas changed the history and trajectory of NoSQL databases.  

What Does Data Management Have To Do With CX?

Companies are in a race to set themselves apart from the competition in a meaningful way. Pre-Internet and pre-cloud, beating the competition meant out-advertising them, out-spending them, out-maneuvering them, or getting to a certain demographic before they did.  

Why Your RDBMS Fails At Scale

Relational databases had their day and are still viable for certain use cases, but the advent of the cloud and subsequent proliferation of cloud applications is putting an almost unmanageable burden on their capabilities. Read this ebook to learn why your RBMS fails at scale, and why it's no longer a viable option for today's distributed, super fast-paced, cloud-friendly world.  

Time To Innovate - Introducing DataStax Managed Cloud

The age of the cloud has brought near oppression levels of data on DevOps teams and their legacy solutions. Even other NoSQL solutions are having trouble keeping up because of the way they shard and the internal resources required to maintain them. Now – there’s finally something powerful enough for the cloud but hands-free and agile enough to let you innovate without worrying about operations: DataStax Managed Cloud. Read this ebook to get the full picture of how it works.  

The 7 Ways A 360-Degree Customer View Helps Banks

The banking industry is getting cluttered with intrepid newcomers – cloud-born digital natives that don’t care if their simple cloud application has the power to take down an entire generation of traditional players. The primary advantage these companies have is in the way they’re using their data. Read this ebook to learn what a 360-degree customer view is and why it’s so important for staying viable as a financial services company in the cloud age.  

Data Security and Payment Cards: Compliance for Always-On Data at Scale

Any organization that deals with payment card data has a laundry list of rules and regulations to worry about. This ebook explains how Thales e-Security and DataStax allow organizations to maintain compliance and safely use sensitive data within the DataStax platform with protection for data stores, system logs, configurations, and more at the file system level.  

Is Your Company Ready to Accelerate its Customer Experience?

The new “gold ring” of customer service is customer experience – specifically, real-time customer experience that makes every customer feel like your only customer. But to get started on this journey there’s a list of things every company needs to seriously consider. This ebook explores the 10 questions you need to ask yourself and your company to get started on your customer experience journey.  

Modernizing Financial Services With DataStax Enterprise

Today’s Financial Services organizations have a huge opportunity: capitalize on always-on data management to completely reinvent their offerings for the modern-day customer. Not doing this could mean falling way behind their competitors and losing out on whole new ways to create customer loyalty, power mission-critical cloud applications, and reduce and protect against fraud. This ebook discusses the various ways banks can leverage DataStax Enterprise for their benefit.  

Modernizing Banks With DataStax Enterprise

Banks deal with mountains of data and complex transactions that far too often don’t capitalize on the power of an always-on, real-time data management platform to provide both financial insights and peace of mind. Today’s cloud applications require a new, far more holistic approach to data management and data protection. This ebook explains why the scalability, 100% availability, enterprise-grade security, and real-time insights of DataStax Enterprise are essential for banking in the modern world.  

For Banks, It's Evolve Or Die

New FinTech players are disrupting industry stalwarts by using their data to their advantage and to build powerful, customer-facing cloud applications. Read this ebook to learn how banks can use the data layer to get ahead of the competition, and how five banking leaders are doing just that using the always-on data management platform by DataStax.  

Big Data vs. Real-Time Data

Big data used to be the “next big thing”. It’s still important, for sure, but as a standalone concept it’s been ​failing to deliver value when it comes to matching the incredibly high demands of today’s “right-now” economy and for creating ​real-time customer experiences. Read this ebook to learn why you need to be using both big AND real-time data to drive true digital transformation and to ​power​ great ​customer experience ​in the moment.  

Simplifying Data Management with DataStax and Robin Application Virtualization Platform

Robin Systems has teamed up with DataStax so that administrators can deploy DSE on Robin’s application-aware infrastructure software which is optimized for container technologies.Robin Systems together with DataStax, provide the complete package for data management, where the data administrators and consumers can just focus on their use cases, while the tedious tasks of deployment, backups, restore, clone, scaling, and performance management are completely automated. This greatly improves IT productivity, and enables them to support and deliver on the promise of agility.  

Using Real-Time Data Management to Drive GDPR Compliance

The European Union's new GDPR (General Data Protection Regulation) affects all companies that process the data of EU residents. Read this ebook to learn what you need to do make your business complaint and why having a top-class data platform is essential for avoiding major fines.  

The 5 Features of an Always-On Data Platform

You need to drive innovation and growth with your critical cloud applications but have a sinking feeling that your current technology isn’t cutting it. There’s a key reason for that: it’s not always there for you. When it comes to database technology, you need to understand what makes an always-on data platform so valuable. Read this ebook to learn the 5 ingredients of an always-on data platform. From scalability to speed, you’ll know exactly why always-on is only the way to go in today’s fast-paced, 24/7 data world.  

The Evolution of Big Data: NoSQL, Hadoop, Spark & Beyond

As the big data ecosystem continues to expand, new technologies are helping companies benefit from the rich sources of information flowing into their organizations. The most pressing areas include real-time data processing, analytics, data integration, governance, and security. Download this report for a better understanding of the current landscape, emerging best practices and real-world successes.  

Why Graph?

A Look at How Cloud Applications Benefit From Graph Technology. There are a variety of different use cases to which a graph database can be applied and where a graph is a better fit than other DBMS’s such as a relational or general NoSQL database.  

The Multi-Model Data Management Platform

Understanding the why’s and how’s of a multi-model database requires a brief look back at the various evolutions of data management that have brought things to where they are today. Read this white paper to learn why multi-model data management platforms became so important, and why today’s cloud applications absolutely require a multi-model approach to data management.  

Is Your Competition Killing You with Personalization?

Customers demand speed, convenience, and in-context experiences. Netflix, Mint Bills, and Clear Capital know their customers won't give them a second chance. Learn how these leaders use DataStax Enterprise to provide an experience their customers can't get anywhere else.  

Simplifying Data Management with DataStax Enterprise OpsCenter

Managing and optimizing the performance of a widely distributed database that is comprised of many individual servers can be very challenging. This paper discusses how DataStax OpsCenter can be used to greatly simplify the task of administering one or many Apache Cassandra™ and DataStax Enterprise database clusters, whether they’re deployed on-premises or in the cloud.  

Cracking the Energy Industry’s Data Dilemma

The oil industry is awash with data. Most companies struggle just to collect, store and analyze all this information. Yet the lack of real-time responsiveness limits the benefits of all this data. The competitive advantage for companies operating in the oilfields of the future will depend on their ability to process vast amounts of data on a large scale, and provide real-time actionable intelligence to remote locations that will improve operating efficiency, safety and maintenance.  

Evaluating Data Management Platforms for Cloud Applications

For any business that wants to successfully compete in today’s digital economy, it’s not a question of if but rather how much of their business will be done with cloud applications. Download this free white paper and explore how DataStax customers are delivering real-time value at epic scale with their cloud applications.  

Financial Services: Simplifying Market Tick Data Management

This paper examines the challenges Financial Services Institutions (FSIs) face when building a market tick data management system, what database requirements the Line of Business (LoBs) should look into, and how the database can be used to provide high throughput and resilience with low latency.  

5 Steps to Apache Cassandra™ Success with DataStax

This paper is an introduction to the 5 steps of a proven methodology for implementing DataStax Enterprise in a production environment. It is intended for IT Operations Managers / DBAs and Centralized IT Management (CIOs, CTOs, etc.) who will be involved in the implementation and ongoing management of the database platform supporting their critical Web, mobile and IoT applications.  

Benchmarking Top NoSQL Databases

Apache Cassandra, Couchbase, HBase, and MongoDB
End Point, a database expert and full-service ecommerce consulting company, performed a series of performance tests on ​leading ​NoSQL ​database ​vendors​. ​The​ overall conclusion​ shows ​Cassandra ​ significantly ​outperform​​ing​ ​the​ ​most recent version of​ ​other NoSQL databases​, including Couchbase 3.0, MongoDB 3.0 (with the Wired Tiger storage engine)​ and HBase 0.98, in throughput and latency..  

Implementing Search in Web, Mobile and IoT Applications

An Overview of DataStax Enterprise Search
This paper describes the general search requirements that most web, mobile and IoT applications have, and the common ways enterprises have tried to deploy search systems in the past. It then describes how NoSQL database systems are fast becoming the standard database platform for these types of applications and why DataStax Enterprise, with its integrated enterprise search capabilities, can make developing powerful search components for an application fast, easy, and cost effective.  

How Transactional Analytics is Changing the Future of Business

This business paper explores how DataStax Enterprise makes it easy for Internet Enterprises to run operational analytics on data stored in Cassandra, and integrate insights with historical Hadoop data warehouses/lakes. By leveraging data collected from operational (transactional) systems organizations you can achieve fast time-to-insight so that online applications can lead to better business.  

The Modern Online Application for the Internet Economy: 5 Key Requirements that Ensure Success

Applications that succeed in today’s digital, Internet economy age are those that interact intelligently with the end customer in specifically tailored and personalized ways, benefitting both the customer and the underlying business. Explore the key five application requirements that an underlying data management platform must provide to enable today’s Web and mobile applications that quickly make new customers and keep them coming back.  

The Internet Enterprise: Making Data the Centerpiece of your Business

This paper defines the “Internet Enterprise” and discusses radical changes in technology DNA that Internet Companies created. Learn how to transform your traditional business to an Internet Enterprise and understand how all forward-looking companies need to challenge long-held assumptions about how they develop and deliver products and services with an eye toward competitive edge.  

DataStax Enterprise Reference Architecture

This white paper outlines the reference architecture of Apache Cassandra™ and DataStax Enterprise (DSE) and establishes a starting point for users who are contemplating different hardware choices to host DSE. This document also provides good guidance for System Architects and System Administrators during the planning stages of development, test and production environments, whether in-house or at a private or public data center.  

Enabling PCI-DSS Compliance on DataStax Enterprise

Today’s online debit, credit and pre-paid card applications need always-on, disaster-proof database technology along with the enterprise security necessary to meet tough industry standards. This paper examines how DataStax Enterprise, powered by the Apache Cassandra™ database, meets these needs in one integrated solution.  

Comparing Oracle with Cassandra/DataStax Enterprise

This paper looks at why NoSQL technology like Apache Cassandra™ / Datastax Enterprise is quickly becoming the first and best database choice over Oracle for online applications, providing guidelines for when a legacy RDBMS like Oracle should be used and when NoSQL is required.  

Why NoSQL?

Today's Right-Now Enterprises need Right-Now Applications for Right-Now Customers. This means having a data layer that's nimble, flexible, scalable, and always on. This white paper explains the need for NoSQL databases, why NoSQL data management has replaced relational data management, and the six reasons companies need NoSQL technology if they are going to thrive in the Right-Now Economy.  

Introduction to Multi-Data Center Operations

Get a solid grounding in why multiple data center databases are fast becoming the new norm for database operations, along with what characteristics a database must have to run simultaneously across many data centers and the cloud.  

Why Migrate from MySQL to Cassandra

Get a high-level examination of the why’s and how’s of migrating from Oracle’s MySQL to more capable big data technologies, such as Apache Cassandra and Apache Hadoop.  

Big Data – Beyond the Hype

This paper examines the growing prevalence of big data across nearly every industry and explains why its effective use is critical for firms that want to compete in their chosen market.  

NoSQL in the Enterprise

Cut through the clutter of varying NoSQL solutions and examine essential characteristics successful enterprise deployments share in common.  

Introduction to Apache Cassandra

Learn about Apache Cassandra, the NoSQL database designed for big data applications that require high performance, massive scale and continuous availability.  

ebook: DBA’s Guide to NoSQL and DataStax Enterprise

As a database administrator, you need to be on top of what's happening in the database world and what's the best type of database for your company. NoSQL databases have surged in popularity, but what is their real value and how might they be a fit for you? This ebook provides a comprehensive look at the NoSQL world, going through all possible use cases, the NoSQL architecture, operations, administration, and the advantages of NoSQL databases over relational databases.