anchor.diff:              let (normspec,weights) = getNormalizedSpec ndx
   
               let f_min kmin = 
  +                printfn "INDEX_SCAN_MIN"
                   let sql_min = sprintf "SELECT DISTINCT d.bson FROM \"%s\" d INNER JOIN \"%s\" i ON (d.did = i.doc_rowid) WHERE k >= ?" tblColl tblIndex
                   let stmt = conn.prepare(sql_min)
                   stmt.bind_blob(1, kmin)
                   stmt
   
               let f_max kmax =
  +                printfn "INDEX_SCAN_MAX"
                   let sql_max = sprintf "SELECT DISTINCT d.bson FROM \"%s\" d INNER JOIN \"%s\" i ON (d.did = i.doc_rowid) WHERE k <= ?" tblColl tblIndex
                   let stmt = conn.prepare(sql_max)
                   stmt.bind_blob(1, kmax)
                   stmt
   
               let f_both (kmin,kmax) =
  +                printfn "INDEX_SCAN_BOTH"
                   let sql_both = sprintf "SELECT DISTINCT d.bson FROM \"%s\" d INNER JOIN \"%s\" i ON (d.did = i.doc_rowid) WHERE k >= ? AND k <= ?" tblColl tblIndex
                   let stmt = conn.prepare(sql_both)
                   stmt.bind_blob(1, kmin)
  
positive.code:                 update = fn_update
                  delete = fn_delete
                  getSelect = fn_getSelect
                  commit = fn_commit
                  rollback = fn_rollback
              }
  
negative.code:                     | Some ndxu ->
                          getStmtForIndex ndxu
                      | None ->
                          printfn "TABLE_SCAN"
                          let collTable = getTableNameForCollection db coll
                          conn.prepare(sprintf "SELECT bson FROM \"%s\"" collTable)
  
  