title: Do I still need to create composite index explicitly if I have a composite unique constraint
body: <p>I have a table with unique constraint</p>
  
  <pre><code>create table if not exists watchlist(
      _id integer primary key autoincrement, 
      country text not null, 
      name text not null, 
      unique (country, name) on conflict replace
  );
  </code></pre>
  
  <p>Since my query will involved <code>country</code> and <code>name</code> in WHERE clause most of the time. To speed up query, I was wondering do I still need to create</p>
  
  <pre><code>create index idx_country_name on watchlist(country, name);
  </code></pre>