Обсуждение: relation_byte_size()

Hackers

Here is the definition of relation_byte_size() in optimizer/path/costsize.c:

----------------------------------------------------------------------
/** relation_byte_size*        Estimate the storage space in bytes for a given number of tuples*        of a given
width(size in bytes).*/
 
static double
relation_byte_size(double tuples, int width)
{       return tuples * (MAXALIGN(width) + MAXALIGN(sizeof(HeapTupleData)));
}

----------------------------------------------------------------------

Shouldn't this be HeapTupleHeaderData and not HeapTupleData ? 

(Of course, from a costing perspective these shouldn't be very different but ...)

-- 
Pip-pip
Sailesh
http://www.cs.berkeley.edu/~sailesh

Your patch has been added to the PostgreSQL unapplied patches list at:
http://momjian.postgresql.org/cgi-bin/pgpatches

I will try to apply it within the next 48 hours.

---------------------------------------------------------------------------


Sailesh Krishnamurthy wrote:
> 
> Hackers
> 
> Here is the definition of relation_byte_size() in optimizer/path/costsize.c:
> 
> ----------------------------------------------------------------------
> /*
>  * relation_byte_size
>  *        Estimate the storage space in bytes for a given number of tuples
>  *        of a given width (size in bytes).
>  */
> static double
> relation_byte_size(double tuples, int width)
> {
>         return tuples * (MAXALIGN(width) + MAXALIGN(sizeof(HeapTupleData)));
> }
> 
> ----------------------------------------------------------------------
> 
> Shouldn't this be HeapTupleHeaderData and not HeapTupleData ? 
> 
> (Of course, from a costing perspective these shouldn't be very different but ...)
> 
> -- 
> Pip-pip
> Sailesh
> http://www.cs.berkeley.edu/~sailesh
> 
> 
> 
> ---------------------------(end of broadcast)---------------------------
> TIP 5: Have you checked our extensive FAQ?
> 
>                http://www.postgresql.org/docs/faqs/FAQ.html
> 

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
359-1001+  If your life is a hard drive,     |  13 Roberts Road +  Christ can be your backup.        |  Newtown Square,
Pennsylvania19073
 

Patch applied.  Thanks.

---------------------------------------------------------------------------


Sailesh Krishnamurthy wrote:
> 
> Hackers
> 
> Here is the definition of relation_byte_size() in optimizer/path/costsize.c:
> 
> ----------------------------------------------------------------------
> /*
>  * relation_byte_size
>  *        Estimate the storage space in bytes for a given number of tuples
>  *        of a given width (size in bytes).
>  */
> static double
> relation_byte_size(double tuples, int width)
> {
>         return tuples * (MAXALIGN(width) + MAXALIGN(sizeof(HeapTupleData)));
> }
> 
> ----------------------------------------------------------------------
> 
> Shouldn't this be HeapTupleHeaderData and not HeapTupleData ? 
> 
> (Of course, from a costing perspective these shouldn't be very different but ...)
> 
> -- 
> Pip-pip
> Sailesh
> http://www.cs.berkeley.edu/~sailesh
> 
> 
> 
> ---------------------------(end of broadcast)---------------------------
> TIP 5: Have you checked our extensive FAQ?
> 
>                http://www.postgresql.org/docs/faqs/FAQ.html
> 

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
359-1001+  If your life is a hard drive,     |  13 Roberts Road +  Christ can be your backup.        |  Newtown Square,
Pennsylvania19073