Advantages of Nosql:
Simple extension (adding a field to a record only needs to add a key:value to that record to add a field, but in a relational database you must add a field to all records)
Flexible data model
Fast read and write (MongoDB takes about one second to write 15,000 records <about 16 seconds on my own computer>, relational databases are much slower)
Disadvantages of Nosql:
Does not provide support for Sql
The supported features are not rich enough (there is no concept of transactions, triggers cannot be written, etc.)
Existing products are not mature enough (because it is a new thing, maturity is also a relative concept)
Classification of NoSql databases:
key-value storage
Memcached、Redis
column store
HBase
Graph database
Document type
MongoDB
Features of MongoDB:
high performance
Easy to store data
collection-oriented storage
pattern freedom
Support dynamic query
index support
Support for replication and failover
Use efficient binary data storage, including large objects
The object size format is BSON (an extension of JSON)
Applicable scenarios of MongoDB
Agile development
Analytics and Logs
cache
Mutable Schema