doc: Small wording change for clarity

From: Martín Marqués <martin@2ndquadrant.com>

doc/src/sgml/plpgsql.sgml

@@ -528,7 +528,7 @@ $$ LANGUAGE plpgsql;
      </para>
 
      <para>
-      The same effect can be had by declaring one or more output parameters as
+      The same effect can be obtained by declaring one or more output parameters as
       polymorphic types.  In this case the
       special <literal>$0</literal> parameter is not used; the output
       parameters themselves serve the same purpose.  For example:

doc/src/sgml/ref/create_function.sgml

@@ -753,7 +753,7 @@ SELECT * FROM dup(42);
     malicious users from creating objects that mask objects used by the
     function.  Particularly important in this regard is the
     temporary-table schema, which is searched first by default, and
-    is normally writable by anyone.  A secure arrangement can be had
+    is normally writable by anyone.  A secure arrangement can be obtained
     by forcing the temporary schema to be searched last.  To do this,
     write <literal>pg_temp</><indexterm><primary>pg_temp</><secondary>securing functions</></> as the last entry in <varname>search_path</>.
     This function illustrates safe usage: