How to know which Kind of Sequence file it is?

Question

I am new to Hadoop and came across few Sequence files. As I read Sequence File there are 3 ways to create a sequence file. Now I have a sequence file , how do I know which what kind of sequence file it is. How do i read Meta information about that. I need this because, I have got a sequence file and it is expected I create a similar sequence file.

Is there any hadoop command I can use to check this information?

Answer 1

SequenceFile is a flat file consisting of binary key/value pairs. The SequenceFile.Reader acts as a bridge and can read any of the SequenceFile formats.

You don't need to mention the SequenceFile format to the SequenceFile.Reader , by default the reader instance will get these details and decompresses the file according to the codec found in the file format.

Check out examples here:

• Reading and Writing Sequencefile using Hadoop 2.0 Apis

• Reading and Writing SequenceFile Example