[HADOOP-450] Remove the need for users to specify the types of the inputs

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.5.0
• Fix Version/s: 0.6.0
• Assignee: Owen O'Malley
• Reporter: Owen O'Malley
• Created: 11/Aug/06 20:28
• Updated: 08/Jul/09 16:51
• Resolved: 15/Aug/06 20:20

Description

Currently, the application specifies the types of the input keys and values and the RecordReader checks them for consistency. It would make more sense to have the RecordReader define the types of keys that it will produce. Therefore, I propose that we add two new methods to RecordReader:

WritableComparable createKey();
Writable createValue();

Note that I propose adding them to the RecordReader rather than the InputFormat, so that they can specific to a particular input split.

Issue Links

• is duplicated by: HADOOP-372 should allow to specify different inputformat classes for different input dirs for Map/Reduce jobs