unique indices without pg_constraint rows

"Ed L." <pgsql@xxxxxxxxxxxxx> · Fri, 29 Mar 2013 17:04:42 -0600



      I've been looking at unique indices in a PostgreSQL 8.3.x
      cluster.  Some unique indices clearly have a corresponding row in
      pg_constraint, while other unique indices appear to have no
      corresponding row in pg_constraint at all.

      
      Why is this?  What determines if a unique index will also have a
      row in pg_constraint?

      
      Thanks in advance.

      
      Ed