Thread

  1. FOR PORTION OF gram.y target_location seems wrong

    jian he <jian.universality@gmail.com> — 2026-04-24T01:10:47Z

    Hi.
    
    | FOR PORTION OF ColId FROM a_expr TO a_expr
        {
            ForPortionOfClause *n = makeNode(ForPortionOfClause);
            n->range_name = $4;
            n->location = @4;
            n->target_start = $6;
            n->target_end = $8;
            n->target_location = @5;
            $$ = (Node *) n;
        }
    
    n->target_location = @5;
    
    Should be
    
    n->target_location = @6;
    
    It's not reachable because of queries like:
    
    UPDATE for_portion_of_test
      FOR PORTION OF valid_at FROM NULL TO NULL
      SET name = 'NULL to NULL';
    
    won't reach
    ereport(ERROR,
            (errmsg("FOR PORTION OF target was null")),
            executor_errposition(estate, forPortionOf->targetLocation));
    
    typedef struct ForPortionOfClause
    {
        NodeTag        type;
        char       *range_name;        /* column name of the range/multirange */
        ParseLoc    location;        /* token location, or -1 if unknown */
        ParseLoc    target_location;    /* token location, or -1 if unknown */
        Node       *target;            /* Expr from FOR PORTION OF col
    (...) syntax */
        Node       *target_start;    /* Expr from FROM ... TO ... syntax */
        Node       *target_end;        /* Expr from FROM ... TO ... syntax */
    } ForPortionOfClause;
    
    Generally, we place ParseLoc at the end of the node, putting it
    elsewhere should be fine.
    But here, we have two comments, ``/* token location, or -1 if unknown */``.
    The "token" is ambiguous, perhaps it's worth the trouble to enhance it?
    
    
    
    --
    jian
    https://www.enterprisedb.com/
    
    
    
    
  2. Re: FOR PORTION OF gram.y target_location seems wrong

    Peter Eisentraut <peter@eisentraut.org> — 2026-04-27T10:04:54Z

    On 24.04.26 03:10, jian he wrote:
    > Hi.
    > 
    > | FOR PORTION OF ColId FROM a_expr TO a_expr
    >      {
    >          ForPortionOfClause *n = makeNode(ForPortionOfClause);
    >          n->range_name = $4;
    >          n->location = @4;
    >          n->target_start = $6;
    >          n->target_end = $8;
    >          n->target_location = @5;
    >          $$ = (Node *) n;
    >      }
    > 
    > n->target_location = @5;
    > 
    > Should be
    > 
    > n->target_location = @6;
    
    I think the existing code is fine.  The target consists of the start and 
    the end value.  If we pointed to @6 then one could be confused into 
    thinking that only the start value is meant.