HBase : Confusion between COLUMN and FILTER (SingleColumnValueFilter)

Question

I have installed hbase and I have access to command's shell.

I have a table with 2 familly column like this:

create 'arbres', 'emplacement', 'propriete'

This request works fine :

scan 'arbres',{FILTER=>"SingleColumnValueFilter('emplacement', 'lieu_adresse', =,'binary:VOIE INCONNUE')", COLUMNS=>['emplacement'], COLUMN=>15}

But this second one, list all rows, without filter

scan 'arbres',{FILTER=>"SingleColumnValueFilter('emplacement', 'lieu_adresse', =,'binary:VOIE INCONNUE')", COLUMNS=>['propriete'], COLUMN=>15}

I don't understand why and I don't find the reason in the documentation.

Please can you explain a little the reason.

regards

Answer 1

The second command has a filter on different column family and column that you are not accessing.

The push down requires the columns to be accessed, meaning you should have the column family and column mentioned in the COLUMNS=>[]

The reason one would have two different column families is to make access easier and light weight, since each column family will have its own file.