BSON
| Filename extension | .bson |
|---|---|
| Internet media type | none[1] |
| Type of format | Data interchange |
| Extended from | JSON |
| Standard | no RFC yet |
| Website | bsonspec |
BSON /ˈbiːsɒn/ is a computer data interchange format used mainly as a data storage and network transfer format in the MongoDB database. It is a binary form for representing simple data structures and associative arrays (called objects or documents in MongoDB). The name "BSON" is based on the term JSON and stands for "Binary JSON".[2]
Data types and syntax
BSON documents (objects) consist of an ordered list of elements. Each element consists of a field name, a type, and a value. Field names are strings. Types include:
- string
- integer (32- or 64-bit)
- double (64-bit IEEE 754 floating point number)
- date (integer number of milliseconds since the Unix epoch)
- byte array (binary data)
- boolean (
trueandfalse) - null
- BSON object
- BSON array
BSON types are nominally a superset of JSON types (JSON does not have a date or a byte array type, for example[3]), with one exception of not having a universal "number" type as JSON does.
Efficiency
Compared to JSON, BSON is designed to be efficient both in storage space and scan-speed. Large elements in a BSON document are prefixed with a length field to facilitate scanning. In some cases, BSON will use more space than JSON due to the length prefixes and explicit array indices.[2]
Example
A document such as {"hello":"world"} will be stored as:
Bson:
\x16\x00\x00\x00 // total document size
\x02 // 0x02 = type String
hello\x00 // field name
\x06\x00\x00\x00world\x00 // field value (size of value, value, null terminator)
\x00 // 0x00 = type EOO ('end of object')
See also
- JSON
- Smile (binary JSON)
- UBJSON
- Protocol Buffers
- Action Message Format
- Apache Thrift
- MessagePack
- Document-oriented database
- Abstract Syntax Notation One (ASN.1)
- Wireless Binary XML (WBXML)
- Efficient XML Interchange
- Sereal
