Editing Data engineering (section)

==== Databases ====
If the data is structured and some form of [[online transaction processing]] is required, then [[databases]] are generally used.<ref name="mit">{{cite web |title=Lecture Notes {{!}} Database Systems {{!}} Electrical Engineering and Computer Science {{!}} MIT OpenCourseWare |url=https://ocw.mit.edu/courses/6-830-database-systems-fall-2010/pages/lecture-notes/ |website=ocw.mit.edu |access-date=31 July 2022}}</ref> Originally mostly [[relational database]]s were used, with strong [[ACID]] transaction correctness guarantees; most relational databases use [[SQL]] for their queries. However, with the growth of data in the 2010s, [[NoSQL]] databases have also become popular since they [[Horizontal scaling#Horizontal and vertical scaling|horizontally scaled]] more easily than relational databases by giving up the ACID transaction guarantees, as well as reducing the [[object-relational impedance mismatch]].<ref name="leavitt">{{cite journal |last1=Leavitt |first1=Neal |title=Will NoSQL Databases Live Up to Their Promise? |journal=Computer |date=February 2010 |volume=43 |issue=2 |pages=12–14 |doi=10.1109/MC.2010.58 }}</ref> More recently, [[NewSQL]] databases — which attempt to allow horizontal scaling while retaining ACID guarantees — have become popular.<ref name="aslett2012">{{cite web |url=http://cs.brown.edu/courses/cs227/archives/2012/papers/newsql/aslett-newsql.pdf |title=How Will The Database Incumbents Respond To NoSQL And NewSQL? |first=Matthew |last=Aslett |publisher=451 Group |publication-date=April 4, 2011 |year=2011 |access-date=February 22, 2020}}
</ref><ref name="sigmodrecord">{{cite conference |first1=Andrew |last1=Pavlo |first2=Matthew |last2=Aslett |title=What's Really New with NewSQL? |book-title=SIGMOD Record |year=2016 |url=https://db.cs.cmu.edu/papers/2016/pavlo-newsql-sigmodrec2016.pdf |access-date=February 22, 2020}}
</ref><ref>{{cite web |url=https://cacm.acm.org/blogs/blog-cacm/109710-new-sql-an-alternative-to-nosql-and-old-sql-for-new-oltp-apps/fulltext |title=NewSQL: An Alternative to NoSQL and Old SQL for New OLTP Apps |first=Michael |last=Stonebraker |publisher=Communications of the ACM Blog |date=June 16, 2011 |access-date=February 22, 2020}}</ref><ref name="high scalability">{{cite web |url=http://highscalability.com/blog/2012/9/24/google-spanners-most-surprising-revelation-nosql-is-out-and.html |title=Google Spanner's Most Surprising Revelation: NoSQL is Out and NewSQL is In |first=Todd |last=Hoff |date=September 24, 2012 |access-date=February 22, 2020}}</ref>