How may versions does HBase MapReduce reads when MapReduce is run on a table ?

Question

假设您有一个HBase表，当在表上运行map reduce时，该表支持版本控制。默认情况下，在Map阶段读取了多少版本，以及如何更改此行为？

Answer 1

Default versions gets created when you hit create 'test', 'cf' is 3

But when you scan in hbase shell

scan 'test' =>returns only latest versions.

scan 'test', {VERSIONS => 3} =>returns 3 versions if it's available.

In Java default scan always return latest but you can force to get previous versions by having this line

scan.setMaxVersions(int maxVersions);