Key Value Use Case

OrientDB can also be used as a Key Value DBMS by using the super fast Indexes. You can have as many Indexes as you need.

HTTP

OrientDB RESTful HTTP protocol allows to talk with a OrientDB Server instance using the HTTP protocol and JSON. OrientDB supports also a highly optimized Binary protocol for superior performances.

Operations

To interact against OrientDB indexes use the four methods of the HTTP protocol in REST fashion:

  • PUT, to create or modify an entry in the database
  • GET, to retrieve an entry from the database. It's idempotent that means no changes to the database happen. Remember that in IE6 the URL can be maximum of 2,083 characters. Other browsers supports longer URLs, but if you want to stay compatible with all limit to 2,083 characters
  • DELETE, to delete an entry from the database

Create an entry

To create a new entry in the database use the Index-PUT API.

Syntax: http://<server>:[<port>]/index/<index-name>/<key>

Example:

HTTP PUT: http://localhost:2480/index/customers/jay

{
  "name" : "Jay",
  "surname" : "Miner"
}

HTTP Response 204 is returned.

Retrieve an entry

To retrieve an entry from the database use the Index-GET API.

Syntax: http://<server>:[<port>]/index/<index-name>/<key>

Example:

HTTP GET: http://localhost:2480/index/customers/jay

HTTP Response 200 is returned with this JSON as payload:

{
  "name" : "Jay",
  "surname" : "Miner"
}

Remove an entry

To remove an entry from the database use the Index-DELETE API.

Syntax: http://<server>:[<port>]/index/<index-name>/<key>

Example:

HTTP DELETE: http://localhost:2480/index/customers/jay

HTTP Response 200 is returned

Step-by-Step tutorial

Before to start assure you've a OrientDB server up and running. In this example we'll use curl considering the connection to localhost to the default HTTP post 2480. The default "admin" user is used.

Create a new index

To use OrientDB as a Key/Value store we need a brand new manual index, let's call it "mainbucket". We're going to create it as UNIQUE because keys cannot be duplicated. If you can have multiple keys consider:

  • creating the index as NOTUNIQUE
  • leave it as UNIQUE but as value handle array of documents

Create the new manual unique index "mainbucket":

> curl --basic -u admin:admin localhost:2480/command/demo/sql -d "create index mainbucket UNIQUE STRING"

Response:

{ "result" : [ 
    { "@type" : "d" , "@version" : 0, "value" : 0, "@fieldTypes" : "value=l" }
  ]
}

Store the first entry

Below we're going to insert the first entry by using the HTTP PUT method passing "jay" as key in the URL and as value the entire document in form of JSON:

> curl --basic -u admin:admin -X PUT localhost:2480/index/demo/mainbucket/jay -d "{'@class': 'V', 'name':'Jay','surname':'Miner'}"

Response:

Key 'jay' correctly inserted into the index mainbucket.

Retrieve the entry just inserted

Below we're going to retrieve the entry we just entered by using the HTTP GET method passing "jay" as key in the URL:

> curl --basic -u admin:admin localhost:2480/index/demo/mainbucket/jay

Response:

[{
  "@type" : "d" , "@rid" : "#3:477" , "@version" : 0,
  "name" : "Jay",
  "surname" : "Miner"
}]

Note that an array is always returned in case multiple records are associated to the same key (if NOTUNIQUE index is used). Look also at the document has been created with RID #3:477. You can load it directly if you know the RID. Remember to remove the # character. Example:

> curl --basic -u admin:admin localhost:2480/document/demo/3:477

Response:

{
  "@type" : "d" , "@rid" : "#3:477" , "@version" : 0,
  "name" : "Jay",
  "surname" : "Miner"
}

Drop an index

Once finished drop the index "mainbucket" created for the example:

> curl --basic -u admin:admin localhost:2480/command/demo/sql -d "drop index mainbucket"
```json
Response:
```json   
{ "result" : [ 
    { "@type" : "d" , "@version" : 0, "value" : 0, "@fieldTypes" : "value=l" }
  ]
}