title: Error while creating index on geometry column
body: <p>I have a table with spatial column(data type geometry) and with around 450k rows. When i tried to add a spatial index on this column, it returns an error as "All parts of a SPATIAL index must be NOT NULL".  </p>
  
  <p>The query to create index is  </p>
  
  <pre><code>create spatial index spatIdx on table_name(ogc_geom)
  </code></pre>
  
  <p>1. Am I doing something wrong?<br>
  2. Where these NULL parts came from?<br>
  3. If its in my spat data how can i remove it (i tried with is null). </p>