A wrapper about lib/pq that auto-prepares queries and caches them.

gistfile1.go

type PgAutoPrepare struct {
	driver.Conn
	cache map[string]driver.Stmt
}

func (pap *PgAutoPrepare) Open(name string) (driver.Conn, error) {
	conn, err := pq.Open(name)
	if err != nil {
		return nil, err
	}
	return &PgAutoPrepare{
		Conn: conn,
		cache: make(map[string]driver.Stmt),
	}, nil
}

func (pap *PgAutoPrepare) Query(query string, args []driver.Value) (driver.Rows, error) {
	stmt, ok := pap.cache[query]
	if ok == false {
		var err error
		stmt, err = pap.Conn.Prepare(query)
		if err != nil {
			return nil, err
		}
		pap.cache[query] = stmt
	}
	return stmt.Query(args)
}

func init() {
	sql.Register("pgautoprepare", &PgAutoPrepare{})
}

If you're worried about it getting crazy, when you add an item to the cache, do:

   if len(pap.cache) > 100 {
      for _, stmt := range pap.cache {
         stmt.Close()
      }
      pap.cache = make(map[string]driver.Stmt)
   }