Databases Reference
In-Depth Information
A collection of name/value pairs. In various languages, this is
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realized as an object, record, dictionary, structure, keyed list, hash
table, or associative array.
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An ordered list of values. In most languages, this is realized as an
array, list, vector, or sequence.
A typical JSON syntax is as follows:
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Data is represented in the form of name-value pairs. A name-
value pair comprises a “member name” in double quotes,
followed by colon “:” and the value in double quotes
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Each data member (name-value pair) is separated by comma
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Objects are held within curly (“{ }”) brackets.
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Arrays are held within square (“[ ]”) brackets.
JSON is significantly like XML:
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JSON is plain text data format
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JSON is human readable and self-describing
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JSON is categorized (contains values within values)
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JSON can be parsed by scripting languages like Java script
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JSON data is supported and transported using AJAX
Though JSON and XML are both data formats, JSON has few advantages over XML
because of the following reasons:
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JSON is lighter compared to XML (No unnecessary/additional
tags in JSON)
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JSON is easier to read and understand by humans.
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JSON is easier to parse and generate for machines.
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For AJAX related applications, JSON is faster than XML.
Column Family Database: Columns, Column Family,
Super Column Family
Column family databases are probably most known because of Google's BigTable
implementation. They are very similar to relational database, but they also have
differences in their approach to storing and accessing data. Some of the difference
is storing data by rows (relational) versus storing data by columns (column family
databases). But a lot of the difference is conceptual in nature. You can't apply the same
sort of solutions that you used in a relational form to a column database.
