reading-notes

Course 301, Entry 11: MongoDB and Mongoose

SQL vs NoSQL

Fill in the chart below with five differences between SQL and NoSQL databases:

SQL

• Relational Databases
• Table-based
• Predefined schema
• Vertically scalable (faster hardware)
• Complex query capable
• Not best fit for Hierarchical data storag
• Very stable

NoSQL

• Non-relational Databases
• Document-based, key-value pairs, graph databases, or wide-column stores
• Dynamic schema
• Horizontally scalable (more servers)
• Simple query capable
• Hierarchical data storage, big data
• Less stable than SQL

SQL vs SQL Summary

SQL: Atomicity, Consistency, Isolation and Durability

NoSQL: Consistency, Availability and Partition tolerance

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What kind of data is a good fit for an SQL database?

Transactional data. For example, oOnline purchases.

What kind of data is a good fit a NoSQL database?

Big data. AI. For example, image matching.

Which type of database is best for hierarchical data storage?

NoSQL

Which type of database is best for scalability?

NoSQL

Terms

SQL

What does SQL stand for?

Structured Query Language

What is a relational database?

A database with a tables that point to each other. The same IDs are used accross multiple tables. A relational database consists of fields within a table. All tables hold same number of fields.

What type of structure does a relational database work with?

One-to-One: one ID to one field

One-to-Many: one ID shared by many fields

Many-to-Many: many IDs shared by many fields

What is a ‘schema’?

Schema are a series of data fields. This data organization is standardized - all tables have the same fields.

NoSQL

What is a NoSQL database?

NoSQL is a database consisting just of tables. There is no schema. There are no relations, but relations can be set manually.

How does it work?

Each table holds its own data. The data is independently pulled from these.

What is inside of a MongoDB database?

A MongoDB database consists of documents, each holding their own data fields and entries. All information is within one place for each table.

Which is more flexible - SQL or MongoDB? and why

NoSQL. Database can easily be updated via horizontal or verticle scaling. Being that it is schema-less, lots of read and write queries can be run.

What is the disadvantage of a NoSQL database?

Duplicate data. Database has to be updated accross different tables.

Things I want to know more about

Case examples for each database.