Original subtitles

‫So what is a database so far we've talked a lot about ask you all, we talked about queries, we talked

‫about why we use Google, we even talked about why it's called a declarative language, but we didn't

‫really talk much about what a database actually is.

‫We gave it a short definition, which was it's a structured set of data that is structured in a certain

‫way to scale with organizations that have massive quantities of data.

‫Now, databases are our modern day interpretation of how to organize data.

‫But before databases were around, we had something called file processing systems.

‫This is the precursor to the modern database.

‫And the reason I'm zooming in on this is because to know where we are, I find it important to know

‫where we came from.

‫So file processing systems were a massive leap ahead, especially in terms of, you know, we used to

‫have cabinet systems and filing systems on paper.

‫These file processing systems were software based and they were a huge leap ahead of whatever we had

‫back in the day.

‫But they had their flaws.

‫First of all, you were saving data on individual files, right?

‫And there was no correlation between the files.

‫What do I mean by that?

‫There were no relationships between the data.

‫You basically were creating systems to save particular types of data.

‫Let's say you had a real estate firm in one part of the system.

‫You would keep all of the listings in the second part of the system.

‫You would keep all of the customers.

‫And in the third part of the system, you would keep all of the sales.

‫But there wasn't really any relationship between the data.

‫Now, what do I mean by that?

‫Of course, what purchases?

‫You would know which customers did the purchase, but the limitation lied in the fact that.

‫If a customer changed over here, the change wouldn't go all the way through to the sale, you basically

‫were copying customer information into the sale.

‫So whenever the customer, let's say, changed their employment or changed their address or changed

‫your phone number, the update would happen here.

‫But the previous sale would not get the reference to the new information.

‫So file processing systems had a lot of benefits, but a lot of negatives because you were building

‫custom software in specific coding languages like Java that would manage your data.

‫You were doing it all, all the programmers, the coders, the developers, whatever you want to call

‫them, they were building their own systems and that's what we call file processing systems.

‫In terms of file processing systems for a user, you would be talking to the computer and some specific

‫coding language, let's say Python or Java would be talking directly to the machinery.

‫And this, like I said, was a large disadvantage because you had all of this management to do in Python

‫or Java or whatever other language you had.

‫The software was so customized to the system, you even needed to know how your data was being stored,

‫what hard drives you were using, what software was running on the server, whether it be Mac, Windows,

‫Linux, you needed to know all of that in order to write the software.

‫So there was a lot of overhead here.

‫On top of that, the user didn't really care about what system was managing the data.

‫Yet every system was specific to what type of data you could build a customer entry software and then

‫you could build a sales software.

‫And all of these systems did not have common ground.

‫What do I mean by that?

‫They were all built custom, so the user needed to know each and every particular system in order to

‫work efficiently, not to mention all of the flaws.

‫So back into the limitations, let's say you had a school system.

‫What you can see here is clearly that the student system, the exam system and the library system were

‫completely independent from each other.

‫So let's say an exam recommended certain books.

‫The exams database didn't necessarily know how the library was storing their data and the library data

‫didn't necessarily know how students were storing their data.

‫All of these systems were independent.

‫That means all of the way that the files were stored were different.

‫There was no common model.

‫Now, what is a model?

‫Well, a model is just a way of saying, hey, my data is going to follow this structure.

‫We're going to have columns and rows and columns.

‫I'm going to put this in Columbia.

‫I'm going to put this.

‫You would put together a system of how your data would be structured.

‫And if all of the data followed a similar model, they could talk to each other.

‫But back in the day they didn't.

‫That means if a student were to loan a book to study for a particular exam, the library would copy

‫the student data and then store it with the rental and the exam would copy the student data when the

‫student took the exam.

‫So you would have a bunch of redundant data, not to mention that all of the data was isolated and none

‫of the systems could talk to each other.

‫These are huge limitations.

‫Now, in comes a data base oriented approach where we migrated to a singular system.

‫This is fascinating.

‫Let's dive a bit deeper into this.