HBase (Easy): How to Perform Range Prefix Scan in hbase shell

Question

I am designing an app to run on hbase and want to interactively explore the contents of my cluster. I am in the hbase shell and I want to perform a scan of all keys starting with the chars "abc". Such keys might inlcude "abc4", "abc92", "abc20014" etc... I tried a scan

hbase(main):003:0> scan 'mytable', {STARTROW => 'abc', ENDROW => 'abc'} 

But this does not seem to return anything since there is technically no rowkey "abc" only rowkeys starting with "abc"

What I want is something like

hbase(main):003:0> scan 'mytable', {STARTSROWPREFIX => 'abc', ENDROWPREFIX => 'abc'} 

I hear HBase can do this quickly and is one of its main selling points. How do I do this in the hbase shell?

Answer 1

So it turns out to be very easy. The scan ranges are not inclusive, the logic is start <= key < end. So the answer is

scan 'mytable', {STARTROW => 'abc', ENDROW => 'abd'} 

Answer 2

In recent versions of HBase you can now do in the hbase shell:

scan 'mytable', {ROWPREFIXFILTER => 'abc'} 

This effectively does this (and also works for binary situations)

scan 'mytable', {STARTROW => 'abc', ENDROW => 'abd'} 

This method is a LOT more efficient than the "PrefixFilter" approach because the latter puts all records through the comparison code the is present in this PrefixFilter class.