Azure data Fundamentals: 2. Describe concepts of relational data

Which one of the following statements is a characteristic of a relational database? ( 1. All data must be stored as character strings 2. A row in a table represents a set of related data 3. Different rows in the same table can contain different columns )

2. A row in a table represents a set of related data

Which one of the following statements is a benefit of using a PaaS service, instead of an on-premises system, to run your database management systems? ( 1. Increased day-to-day management costs 2. Increased scalability 3. Increased functionality )

2. Increased scalability

What is an index?

A structure that enables you to locate rows in a table quickly, using an indexed value

Azure offers several PaaS solutions for relational databases, include

Azure SQL Database, Azure Database for PostgreSQL, Azure Database for MySQL, and Azure Database for MariaDB

The columns marked FK are ____________ columns. They reference, or link to, the primary key of another table, and are used to maintain the relationships between tables

Foreign Key

In many ways, the _________ approach is similar to the way in which you run your systems inside an organization, except that you don't have to concern yourself with buying or maintaining the hardware. However, you're still responsible for many of the day-to-day operations, such as installing and configuring the software, patching, taking backups, and restoring data when needed.

IaaS

You can think of ________ as a transition to fully managed operations in the cloud; you don't have to worry about the hardware, but running and managing the software is still very much your responsibility.

IaaS

You generally have two options when moving your operations and databases to the cloud. You can select an _________ approach, or _________.

IaaS ; PaaS

IaaS is an acronym for _____________

Infrastructure-as-a-Service.

Rather than creating a virtual infrastructure, and installing and managing the database software yourself, a ___________ solution does this for you. You specify the resources that you require (based on how large you think your databases will be, the number of users, and the performance you require), and Azure automatically creates the necessary virtual machines, networks, and other devices for you.

PaaS

PaaS stands for _____________

Platform-as-a-service

In a data model, the columns marked PK are the ____________ for the table

Primary Key

Most relational databases support ____________. You use __________ to create tables, insert, update, and delete rows in tables, and to query data

Structured Query Language (SQL); Structured Query Language (SQL)

A ____________ approach uses virtual technology to host a company's applications offsite. There are no capital expenses, data can be backed up regularly, and companies only have to pay for the resources they use.

cloud-based

Some relational database management systems also support ____________ indexes. A _________ index physically reorganizes a table by the index key. This arrangement can improve the performance of queries still further, because the relational database management system doesn't have to follow references from the index to find the corresponding data in the underlying table

clustered; clustered

All rows in the same table have the same

columns.

Whether a company places its relational workload in the cloud or whether it decides to keep it on premises, __________ will always be paramount

data security

An ___________ is described as a thing about which information needs to be known or held.

entity

An __________ helps you search for data in a table

index

When you create an __________ in a database, you specify a column from the table, and the _________ contains a copy of this data in a sorted order, with pointers to the corresponding rows in the table

index; index

SQL virtual machines are ____________. That is, you can copy your on-premises solution directly to a virtual machine in the cloud.

lift-and-shift

The relational database model was designed to solve the problem of

multiple arbitrary data structures.

to split an entity into more than one table. This process is called

normalization.

The main characteristics of a relational database are:

1. All data is tabular. Entities are modeled as tables, each instance of an entity is a row in the table, and each property is defined as a column. 2. All rows in the same table have the same set of columns. 3. A table can contain any number of rows. 4. A primary key uniquely identifies each row in a table. No two rows can share the same primary key. 5. A foreign key references rows in another, related table. For each value in the foreign key column, there should be a row with the same value in the corresponding primary key column in the other table.

Hosting a relational database _____________ requires that an enterprise not only purchases the database software, but also maintains the necessary hardware on which to run the database. The organization is responsible for maintaining the hardware and software, applying patches, backing up databases, restoring them when necessary, and generally performing all the day-to-day management required to keep the platform operational Scalability is also a concern.

on-premises

The ____________ indicates the column (or combination of columns) that uniquely identify each row. Every table should have a ____________

primary key; primary key

You can define relationships between tables using _______ and ________ keys, and you can access the data in tables using _________.

primary; foreign; SQL

You can use a ____________ database any time you can easily model your data as a collection of tables with a fixed set of columns.

relational

The relational model provided a standard way of

representing and querying data that could be used by any application

The__________ in a table have one or more columns that define the properties of the entity, such as the customer name, or product ID.

rows

A relational database comprises a set of ____

tables

From the beginning, developers recognized that the chief strength of the relational database model was in its use of ___________, which were an intuitive, efficient, and flexible way to store and access structured information.

tables

In a relational database, you model collections of entities from the real world as

tables

Some columns are used to maintain relationships between

tables

One of the main benefits of computer databases is that

they make it easy to store information so it's quick and easy to find.

A _________ is a virtual table based on the result set of a query

view