Hive vs PIG

Hive	PIG
Developed at Facebook	Developed at Yahoo!
Hive is best for structured Data	PIG is best for semi structured data
Hive used for reporting	PIG for programming
Hive used as a declarative SQL	PIG used as procedural language
Hive supports partitions	PIG does not
Hive can start an optional thrift based server	PIG can't
Hive defines tables before hand (schema) + stores schema information in database	PIG don't have dedicated metadata of database
Hive does not support Avro	PIG does
Hive does not	Pig also supports additional COGROUP feature for performing outer joins.
Both Hive & PIG can join, order & sort dynamically

Singleton Class vs Static Class

Singleton Class	Static Class
·         They can be extended	·         Cannot
·         They can be passed around as an object	·         Cannot
·         They can Garbage collected	·         Cannot
·         They can override methods defined in Singleton class by extending it.	·         Cannot as it leads to inflexibility
·         Easy to create mock object for JUnits	·         Difficult to create mock objects and hard to test
·         They can be LAZY loaded if it’s a heavy object	·         Always early loaded
·	·         Better performance as static methods  are bonded at compile time
·         Use when need full  OO capability i.e. inheritance and polymorphism	·         Use when need to store bunch of static methods together