title: performance of using primary key and secondary index in a query in cassandra
body: <p>Lets say there is a table with 3 columns A,B, and C. A is primary key.
  I have 2 types of query, one that searches by A and B and another that searches by A and C.
  Is it better to add a secondary index for C to search based on A and C or make a new table with A, C, and B columns.</p>
  
  <p>To put it in different perspective, in general it is a bad idea to have two secondary indexes on two columns and have a where clause conditioning on both indexes. Is it the same case for combining primary key and a secondary index?</p>
  
  <p><a href="https://www.youtube.com/watch?v=CbeRmb8fI9s#t=56" rel="nofollow">https://www.youtube.com/watch?v=CbeRmb8fI9s#t=56</a></p>
  
  <p><a href="https://www.youtube.com/watch?v=N6UY1y3dgAk#t=30" rel="nofollow">https://www.youtube.com/watch?v=N6UY1y3dgAk#t=30</a></p>