title: How to recreate tsvector column originally populated by tsvector_update_trigger
body: <p>I'm running Postgres 9.4.</p>
  
  <p>I have a column called main_search_index_col that was populated by this trigger:</p>
  
  <pre><code>main_vector_update BEFORE INSERT OR UPDATE ON the_entries 
     FOR EACH ROW EXECUTE PROCEDURE 
     svector_update_trigger('main_search_index_col','pg_catalog.english', 'name', 'location', 'type')
  </code></pre>
  
  <p>I've gone ahead and created a new text search configuration called unaccent_english (public.unaccent_english) to replace pg_catalog.english</p>
  
  <p>I've dropped the above trigger and redone it using public.unaccent_english instead of pg_catalog.english</p>
  
  <p>drop trigger main_vector_update on the_entries;</p>
  
  <pre><code>CREATE TRIGGER main_vector_update BEFORE INSERT OR UPDATE ON the_entries
  FOR EACH ROW EXECUTE PROCEDURE
  tsvector_update_trigger('main_search_index_col','public.unaccent_english', 'name', 'location', 'type');
  </code></pre>
  
  <p>But as I understand it that won't change any of the values in main_search_index_col unless the row is updated or a new row is added.</p>
  
  <p>I instead want to go through and either update main_search_index_col for each row, or drop the column and recreate it completely and populate it as if the trigger in it's new form had always existed.</p>
  
  <p>How do I make the contents of the column main_search_index_col correct for the new trigger?</p>
  
  <p>Also how do I see the exact definition of tsvector_update_trigger?  I have a feeling if I could read the definition of it, it might be helpful in crafting my own solution.</p>