Speaker A
I've got a pop quiz for you. What database system has been around for almost 50 years?
An introduction to relational databases by IBM Technology, covering structure, relationships, and key benefits for developers.
Key Takeaways
- Relational databases use tables and foreign keys to model complex data relationships.
- SQL is the standard language for querying and managing relational data.
- Indexes enhance query speed by maintaining up-to-date caches of column values.
- Transactions and locking ensure data integrity and support concurrent access.
- Stored procedures simplify repetitive query operations and improve maintainability.
What the video covers
- Relational databases have been around for nearly 50 years and remain foundational for data management.
- They organize data into tables representing entities, with rows as records and columns as attributes.
- Relationships between tables are established using foreign keys to link related data.
- Structured Query Language (SQL) is used to query and manipulate data within relational databases.
- Indexes improve query performance by caching frequently accessed column values.
- Relational databases ensure data consistency through transaction management and rollback capabilities.
- Stored procedures allow grouping of SQL queries into reusable blocks, reducing code complexity.
- Concurrency control and locking mechanisms prevent conflicts when multiple users access the database simultaneously.
- The video emphasizes the practical benefits of relational databases for application development.
- It encourages viewers to consider relational databases for their next project and invites engagement.
Chapters
- 00:00Introduction to Relational Databases
- 00:27Characteristics of Relational Database Model
- 00:54Structure: Tables and Records
- 02:23Using SQL to Query Data
- 04:01Indexes and Query Optimization
- 04:50Benefits: Consistency and Transactions
- 05:54Stored Procedures and Views
- 06:41Concurrency and Locking Mechanisms
- 07:34Summary and Call to Action
Full Transcript — Download SRT & Markdown
Speaker A
I guess you can guess it by the topic of this video. It's a relational database.
Speaker A
Hello, my name is Jamil Spain, Developer Advocate with the IBM Cloud and Brand Technical Specialists in the U.S.
Speaker A
Financial Services market. And today's talk, we're going to dive a little bit into relational databases.
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I'm going to get into some of the characteristics of the database model and also some benefits that it provides for you when making your decision that you want to use this for your next project to get started.
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Let's talk about the structure of a relational database system. It's going to pretty much map out your data points and bring out the relationships in that. And the way that it accomplishes that is through.
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The first thing is making tables, which represents particular items or nouns or particular entities of your particular system that you want to actually prototype. So let's say I have a bunch of books.
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Now this is going to be a table. It accomplishes the attributes of these books by having columns and columns will be things like name.
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Date. OK, maybe author. Of course, got to have an author for a book and every.
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Table is going to have an ID, feel some way to uniquely identify it. Each each row of this.
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Database table represents an actual record or an item, a type of book. That's how it really fulfills that ability to hold the database system there.
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And then as you wait, you kind of query out this particular system is through what we call a you will a structured query language.
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And it's a particular system, you can say select. All the books. And give me all this data out for me to use.
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Now we have one particular item here books, but where it really comes, you really see the power of a relational database.
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Let's say now I want to show the authors. And the way that relational databases can really provide the structure of relating these two entities together is by describing them through a particular entity or relationships.
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You have one that you're here about where books can have multiple authors, so maybe a one.
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To many. You can have a one to one. And just a couple of relationships you can you can kind of mirror within the database system, so one way that I can have this kind of a normalized structure is to say
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definitely the authors is going to have. Its own particular ID and name any, any any any particular order of attributes that I want to describe there, but I can also one of these fields can be an actual number
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that actually relates to the ID. Of this feel, and this is what's known as a foreign key.
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And of course, there will be a name there, so when I do my query, the next query I do, I can reference both these tables and say, Hey, give me all the books and give me more of the author
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information from this table using this foreign key to describe that particular structure there. And you can imagine you'll be running a lot of these queries a lot, and there are some benefits or some things that are provided to
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help with those to speed up these queries and make them operate as efficiently as possible.
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You have the database will provide ways that you can kind of set an index. Let's say that I'm often querying and always trying to pull out by name or by date.
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I can set an index. On this particular column, which will automatically index all the values, so the next time you run, this query is going to pull from what we like to call this cache of all the values.
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Most importantly, every time new roles are added, records are added to this particular table. The index keeps building this recent, I like to say, cache of all these values, so it's always keeping up to date to work there.
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So this is all the characteristics of what you kind of have to model out your particular application that you want to build and describe how the entities are related to each other.
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Now let's switch over here to some of the benefits that you're going to get out of the box with a relational database that you want to use.
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The first we'll talk about is actual consistency. Now, this is useful because let's say there is some point where I want to run multiple of these transactions.
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Let's say I'm modeling an inventory system for an E commerce application, and I have the need to write several queries in a row that may manage a couple of different subsystems.
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But if one of those queries fails, I want the option to be able to roll back.
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The whole set of all those queries, just to make sure that my data always maintains some consistency there.
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The second is the option to do stored procedures. Sounds like a very complicated word there.
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But think of store procedures as the ability to write multiple blocks or functions of code, or if there are a certain amount of queries that I continue to always run, I can kind of model these. So it takes me less
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code to write that particular to access that same functionality with less SQL code. And as you start to get into more SQL writing with relational databases, you'll see queries can get pretty big.
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Another way you can do this, as well as another topic code views here. Definitely want to introduce some of these keywords as you do your deeper dove. You were able to see a lot of these and it'd be familiar
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to you. And the last one is a mechanism to handle locking in the database.
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And concurrency. Why is that important? Well, at some point multiple users are going to want to use the database, maybe at the same time, maybe two applications are going to be adding in books.
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And if the first application is making a particular insert into this table. You're going to want to make sure that the database is locked until that right is done and then the second application has its ability to go in and make its insert
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as well. So these are all built into a lot of the relational databases that you use.
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A lot of these benefits will be provided for you out of the box, not necessarily something you'll have to write in code, but just know that you'll have this at top of mind when you are kind of selecting
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to use a relational database for your next project. I hope this is good for you to understand the foundation of relational databases.
Speaker A
Talk to you next time. If you have questions, please drop us a line below.
Speaker A
And if you want to see more videos like this in the future, please like and subscribe.
Topics:relational databaseSQLforeign keydatabase indexingtransactionsstored proceduresdata consistencyconcurrencyIBM Clouddatabase relationships
