So far we have seen basic RDD where elements have been words, numbers, or lines of text. We'll now discuss PairRDD, which are essentially datasets of key/value pairs. People who have been using MapReduce will be familiar with the concept of key/value pairs and their benefits during aggregation, joining, sorting, counting, and other ETL operations. The beauty of having key value pairs is that you can operate on data belonging to a particular key in parallel, which includes operations such as aggregation or joining. The simplest example could be retail store sales with StoreId
as the key, and the sales amount as the value. This helps you perform advanced analytics on StoreId
, which can be used to operate the data in parallel.
Argentina
Australia
Austria
Belgium
Brazil
Bulgaria
Canada
Chile
Colombia
Cyprus
Czechia
Denmark
Ecuador
Egypt
Estonia
Finland
France
Germany
Great Britain
Greece
Hungary
India
Indonesia
Ireland
Italy
Japan
Latvia
Lithuania
Luxembourg
Malaysia
Malta
Mexico
Netherlands
New Zealand
Norway
Philippines
Poland
Portugal
Romania
Russia
Singapore
Slovakia
Slovenia
South Africa
South Korea
Spain
Sweden
Switzerland
Taiwan
Thailand
Turkey
Ukraine
United States