PostgreSQL

Question 1

What is PostgreSQL and what are some alternative relational databases?

Answer 1

PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. PostgreSQL is a tool in the Databases category of a tech stack.

In-Memory Databases.
Hadoop/NoSQL.
Virtualized Databases.
Columnar Databases.
Streaming Databases.

Question 2

What are some advantages of learning a relational database?

Answer 2

1. Categorizing data. Database administrators can easily categorize and store data in a relational database that can then be queried and filtered to extract information for reports. Relational databases are also easy to extend and aren’t reliant on physical organization. After the original database creation, a new data category can be added without having to modify the existing applications.
2. Accuracy. Data is stored just once, eliminating data deduplication in storage procedures.
3. Ease of use. Complex queries are easy for users to carry out with SQL, the main query language used with relational databases.
4. Collaboration. Multiple users can access the same database.
5. Security. Direct access to data in tables within an RDBMS can be limited to specific users.

Question 3

What is one way to see if PostgreSQL is running?

Answer 3

sudo service postgresql status

Question 4

full stack process

Answer 4

1. client sends request to the web server(req)
2. server receives the request(req)
3. server sends a query to the database (INSERT a new row)
4. Database replies to the server with a “result”
5. Server can now send a response to the client

Client and Server are relationships not things
the ‘server’ is a ‘client’ of the database

Question 5

What is a database schema?

Answer 5

A database schema defines how data is organized within a relational database; this is inclusive of logical constraints such as, table names, fields, data types, and the relationships between these entities.

Question 6

what is a table?

Answer 6

list of rows that have the same set of attributes

Question 7

what is a row?

Answer 7

In relational database terms, a row is a collection of fields that make up a record.