About CouchDB

Hi, today I want to introduce you to a nosql db named CouchDB.

Basics, introduction and learn about Couchdb – 2019

What is CouchDB?

Website address: http://couchdb.apache.org/couchbase.com
CouchDB is an open-source NoSQL database, which stores data in the form of document / JSON.
CouchDB is designed to be easy to use and serves the web environment.

Advantages of CouchDB

CouchDB has a RESTFul-style API.
The API RESTFul is easy to manipulate.
Data is stored under the document structure, we do not need to worry about the data structure.
Map / reduce makes filtering, searching, and aggregating data easier than ever.
Cloning / synchronization is the special power of CouchDB that rare databases have.

Data model

Database is the largest data set of CouchDB.
Each database is a list of independent documents.
Document includes user data.
CouchDB uses data versioning mechanism. The goal is to avoid locking data.

Other possibilities

Data is saved as a document

CouchDB is a document-type NoSQL database. Document is a data unit (like an object of Javascript), each field has a unique name that does not match, contains data types such as letters, numbers, Boolean, lists … There is no limit to the content Quantify text or number fields in a document.

CouchDB provides a RESTFul API for reading and writing documents.

The following is an example of a document

{
“id”: “aa”,
“name”: “iocloud”,
“host”: “iocloud.info”
}

CouchDB provides ACID semantics

CouchDB can handle a high volume of concurrent readers and writers without conflict.

Compaction

Compression is an action that frees up the amount of hard drive used by deleting data that is no longer in use.
When executing data compression in a file, a new file with the .compaction format will be created and the data will be copied into this new file.
When the copy process completes, the old file will be deleted. Database is still online during compression and data changes / read operations are still normal.

Views

Data in CouchDB is stored in documents. You can imagine that 1 database is 1 table and 1 document is 1 row. When we want to present data with different perspectives, we need a method to filter, organization to display the final result.

To solve this problem, CouchDB uses the View model. View is a method of aggregating data in documents in a database. Views are dynamically built and without affecting the recorded data of the documents, we can have as many views as you want depending on the data presentation needs.

So I’ve introduced you to CouchDB. Hopefully, through the next post I will talk more and for illustration. Bye and see you again.