Re: HeapTupleHeader without oid - Mailing list pgsql-hackers

From Manfred Koizar
Subject Re: HeapTupleHeader without oid
Date
Msg-id h9n0iuk1nq4a6hhtvoptj92o59qo7l8vtk@4ax.com
Whole thread Raw
In response to HeapTupleHeader withoud oid  (Manfred Koizar <mkoi-pg@aon.at>)
List pgsql-hackers
On Mon, 01 Jul 2002 12:40:35 +0200, I wrote:
>Bytes saved on architectures with 4/8 byte alignment:
>                                  hoff    bytes
>natts  bitmaplen  hoff72  oidoff   woo    saved
>       0          28/32     24    24/24    4/8
>1-8    1          28/32     24    24/24    4/8
>9-40   2-5        32/32     28    28/32    4/0
>41-72  6-9        36/40     32    32/32    4/8

In this table oidoff contains wrong values, it is from my first
approach, where I tried to put oid at the first INTALIGNed position
after t_bits.  The table should be:
      bitmap                        hoff    bytes
natts   len   hoff1  hoff2  oidoff    woo    saved       0      32    28/32   24/28    24      4/8
1-8     1      32    28/32   24/28    24      4/8
9-40    2-5   36/40   32      28     28/32    4/0
41-72   6-9    40    36/40   32/36    32      4/8

where hoff1 is the MAXALIGNed length of the tuple header with a v7.2
compatible tuple header format (with bitmaplen patch included);
hoff2 is the header size after the Xmin/Cid/Xmax patch, which is still
being discussed on -patches and -hackers;
with this proposal, if a table has oids, oidoff is the offset of the
oid and header size equals hoff2;
hoff woo is the header size without oid;
bytes saved is relative to hoff2.

I apologize for the confusion.

ServusManfred




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