BSON
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| Filename extension | .bson |
|---|---|
| Internet media type | application/bson[1] |
| Type of format | Data interchange |
| Extended from | JSON |
| Website | bsonspec |
BSON (/ˈbiːsən/[2]) is a computer data interchange format. The name "BSON" is based on the term JSON and stands for "Binary JSON".[2] It is a binary form for representing simple or complex data structures including associative arrays (also known as name-value pairs), integer indexed arrays, and a suite of fundamental scalar types. BSON originated in 2009 at MongoDB. Several scalar data types are of specific interest to MongoDB and the format is used both as a data storage and network transfer format for the MongoDB database, but it can be used independently outside of MongoDB. Implementations are available in a variety of languages such as C, C++, C#, D, Delphi, Erlang, Go, Haskell, Java, JavaScript, Julia, Lua, OCaml, Perl, PHP, Python, Ruby, Rust, Scala, Smalltalk, and Swift.[3]
Data types and syntax
BSON has a published specification.[4][5] The topmost element in the structure must be of type BSON object and contains 1 or more elements, where an element consists of a field name, a type, and a value. Field names are strings. Types include:
- Unicode string (using the UTF-8 encoding)
- 32 bit integer
- 64 bit integer
- double (64-bit IEEE 754 floating point number)
- decimal128 (128-bit IEEE 754-2008 floating point number; Binary Integer Decimal (BID) variant), suitable as a carrier for decimal-place sensitive financial data and arbitrary precision numerics with 34 decimal digits of precision, a max value of approximately 106145
- datetime w/o time zone (long integer number of milliseconds since the Unix epoch)
- byte array (for arbitrary binary data)
- boolean (
trueandfalse) - null
- BSON object
- BSON array
- JavaScript code
- MD5 binary data
- Regular expression (Perl compatible regular expressions ("PCRE") version 8.41 with UTF-8 support)[6]
An important differentiator to JSON is that BSON contains types not present in JSON (e.g. datetime and byte array) and offers type-strict handling for several numeric types instead of a universal "number" type. For situations where these additional types need to be represented in a textual way, MongoDB's Extended JSON format[7] can be used.
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:
\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
- Comparison of data serialization formats
- JSON
- CBOR
- Smile (binary JSON)
- UBJSON
References
- ↑ "BSON Support in ASP.NET Web API 2.1 - ASP.NET 4.x". 2014-01-20. https://docs.microsoft.com/en-us/aspnet/web-api/overview/formats-and-model-binding/bson-support-in-web-api-21.
- ↑ 2.0 2.1 2.2 "BSON (Binary JSON) Serialization". https://bsonspec.org/.
- ↑ "BSON Implementation Projects". https://bsonspec.org/implementations.html.
- ↑ "BSON (Binary JSON): Specification". https://bsonspec.org/spec.html.
- ↑ "Introducing NoSQL and MongoDB | What Is NoSQL? | InformIT". https://www.informit.com/articles/article.aspx?p=2247310&seqNum=4%20api.mongodb.com/python/current/api/bson/regex.html.
- ↑ "regex – Tools for representing MongoDB regular expressions — PyMongo 3.6.0 documentation". https://api.mongodb.com/python/current/api/bson/regex.html.
- ↑ "MongoDB Extended JSON documentation". https://docs.mongodb.com/manual/reference/mongodb-extended-json/.
External links
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