title: Sorted Key/Value Database solution
body: <p>I'm looking to implement a database solution to support very fast column based access on a set of simple 2D datasets. i.e consider this dataset</p>
  
  <pre><code>==========================================================
                       SOME DATASET1
  ==========================================================
     ENTRY     |    Col1   |   Col2  |    Col3    ... Coln
  ----------------------------------------------------------
     ENTRY A        1.1        0.2         5.5       6.2
     ENTRY B        2.3        6.4         1.5       1.1
     ENTRY C        2.2        4.2         9.5       3.4
     ENTRY D        2.3        1.1         5.5       2.9
     ENTRY E        9.1        3.6         7.5       2.6
  </code></pre>
  
  <p>What I need is a means of simply selecting all values in column1, or column2, or column n, while preserving the sort order. My initial idea was to use redis, with the following keyspace design:</p>
  
  <pre><code>   SOMEDS1/COLUMNS/           =&gt;     Col1, Col2, Col3 ... Coln
     SOMEDS1/ENTRIES/           =&gt;     A, B, C, D, E
     SOMEDS1/Col1/              =&gt;     1.1, 2.3, 2.2, 2.3, 9.1
     SOMEDS1/Coln/              =&gt;     ......
  </code></pre>
  
  <p>The principle behind this design is that the number of entries in each list are not large, perhaps &lt; 10,000 but there may be a lots of columns, and only selected columns are ever needed at a given time. </p>
  
  <p>My question is has anyone implemented anything like this already, and if so can you advice on the most appopriate type of database. My initial thoughts were to go with redis but I'm open to suggestions.</p>