Database Reference
In-Depth Information
require less tooling to interact with in the first place. One potential disadvantage to JSON, depending on
your use case, is that JSON can't be validated directly against a schema as XML can.
JSON is highlighted here because of its frequent use in representing data directly or in examples for
document databases and distributed hash tables; we see a lot more of it throughout this topic.
You can think of document-oriented databases as collections of key-value collections, making
them a kind of predecessor to the key-value stores discussed later in
Key-Value Stores and Dis-
tributed Hashtables
.
Although that's easy to envision, consider a JSON document such as the one
shown here:
{
"title": "I Heart LolCatz",
"author: "Inigo Montoya",
"ts": Date("31-Dec-99 11:59"),
"comments": [{
"author": "Robert Zimmerman",
"comment: "I'm just a song and dance man"}, {
"author": "Rogers Nelson",
"comment: "I'm just a song and dance man"}
]
}
Consider the tables that might be required to represent even this very simple data structure in
a relational database and what the queries might look like. With a document-oriented database,
you store exactly that document, and queries are simple one-liners.
IBM Lotus
Lotus, first released in 1989, was perhaps the inspiration for all the other kinds of document-ori-
ented databases, such as CouchDB and MongoDB. Lotus represents a family of products for col-
laboration, including Lotus Notes and Domino for email, discussion, and calendar; Lotus Same-
time for messaging; and others.
▪
Website
:
http://www.ibm.com/software/lotus
▪
Orientation
: Document
▪
Created
: Lotus was first released in 1989. The most recent version as of this writing is ver-
sion 8.5, released in March 2010.
▪
Schema
: There is no required schema. Documents (“notes”) are stored in a native format
called a Notes Storage File (NSF), but can be thought of for modeling purposes as JSON
documents.
