MongoDB for Developers with Python Transcripts
Chapter: What is NoSQL?
Lecture: NoSQL history

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0:01 Let's begin our exploration of MongoDB at a high level
0:04 with the why and history of NoSQL in general.
0:08 So if you look around the software development landscape
0:11 you'll see that people when they talk about
0:13 how are we going to design our application frequently say
0:15 well let's assume that we have a relational database,
0:18 now we can discuss what type of ORM should we use,
0:22 or should we use an ORM at all,
0:24 or should we use micro services or things like this.
0:26 Basically, the fact that we're starting from a relational database
0:29 is considered to be an axiom of software development,
0:33 we have data, it goes into relational database
0:35 now let's talk about the architecture, now let's talk about scaling,
0:38 let's talk about performance and so on.
0:40 And just to drive home how strong of a statement that is,
0:42 an axiom, recall the exact definition—
0:45 a statement or proposition that is regarded as being self evidently true,
0:49 it's just clear that you start from a relational database.
0:52 So what are the things I hope you take away from this course is
0:55 that the database style, the database engine is a choice,
1:00 it's a really important choice that has actually super important
1:04 and far reaching implication for your application.
1:06 So I want to sort of break this mold
1:09 that starting from a relational database is an axiom.
1:12 Sometimes it makes sense, sometimes it's perfect,
1:15 but a lot of times as you'll see throughout this course
1:17 starting with a document database is actually a better choice.
1:20 Now, what is NoSQL? Ask five people what NoSQL is,
1:24 you'll probably get five different answers back.
1:26 Some people will say, well the 'no' stands for 'not only'
1:31 so NoSQL is 'not only SQL',
1:34 well that's a great open minded view of the world,
1:37 but I'm sorry to say that's not what NoSQL is.
1:40 Maybe it means it doesn't have SQL,
1:44 maybe it means the system operates without the SQL language, right,
1:47 without select * from this etc, without that language.
1:51 If we look at the history, I think you'll see that this is also not the case.
1:55 Here's a toaster, this toaster operates without SQL,
1:58 is it a NoSQL toaster— I don't think so!
2:01 And of course not, it's not a NoSQL toaster, it's just a toaster.
2:05 NoSQL doesn't mean it operates without the SQL query language
2:08 in fact, I believe that document DB, Microsoft's document database
2:13 that runs in Azure, actually more or less uses
2:16 a flavor of the SQL query language to query it.
2:19 So no, it's not about excluding this SQL query language,
2:22 it's something entirely different, so let's next look at the history,
2:26 and I think you'll have a really good idea of what NoSQL is
2:29 and maybe it will come to a little bit closer agreement on the definition of NoSQL.