This document discusses MongoDB, a NoSQL database. It outlines pros including being schemaless, easy integration with programming languages, and using MapReduce for complex queries. Cons mentioned are data redundancy taking more space, inability to do joins, and lack of transactions which impacts consistency for monetary data.

1. NoSQL Databases:
An experience with
Jim Chang

2. Firstly, understand what is

3. MongoDB
MongoDB:
Collections of a lot of JSONs, literally

4. Scalability is excluded in this discussion

5. Pros (1/3): Schemaless
No need to design schema, always ready for different kinds
of data, just put them in the bag
Perfect for dirty
data warehouse!

6. Pros (2/3): Easiness
Strong Integration with programing languages
You don’t have to learn another language
Postgresql in Python:
cur.execute("SELECT * from bar")

7. Pros (3/3): MapReduce
Ultimate solution for complicated queries

8. A simple MapReduce snippet (1/2)

9. A simple MapReduce snippet (2/2)

10. Cons(1/3): Redundancy
It takes more space than SQL does,
because of the repetitive fields

11. Cons(2/3): No Joins
Repetitive Design Relational Design
Not suitable for “Relational” data design
Why You Should Never Use MongoDB (Sarah Mei)
http://www.sarahmei.com/blog/2013/11/11/why-you-should-never-use-mongodb/

12. Cons(3/3): No transactions
No transactions, the default configuration is not for
consistency-concerned issue.
Be careful if you want to handle monetary data
MongoDB, E-commerce and Transactions (Steven Francia)
http://www.slideshare.net/spf13/mongodb-ecommerce-and-
transactions-10524960

13. 1. Schemaless
2. Easiness
3. MapReduce
1. Redundancy
2. No joins
3. No transactions