Re: (Updated) Table File Format - Mailing list pgsql-hackers

From Michael Richards
Subject Re: (Updated) Table File Format
Date
Msg-id 030a01c065e6$49e21290$0200a8c0@digitallis
Whole thread Raw
In response to (Updated) Table File Format  ("Michael Richards" <miker@interchange.ca>)
List pgsql-hackers
Okay,

Where would I find a definition of the tuple data? I didn't see anything
promising in include/storage?

I've found a definition for the page inside pagebuf.h That clears up all the
page stuff. I'm still having a little trouble decoding the tuple data
within. Hannu Krosing sent me a python script to do the extract, but having
never seen a line of Python before in my life, I'm having a little trouble
with the actual tuple data. I can see where the actual transaction
visibility info is in the tuple data, but the actual data... nope. My
program (c++) is at the point where it will create tuple objects for every
block of "tuple" data within the page.

thanks
-Michael

----- Original Message -----
From: "Tom Lane" <tgl@sss.pgh.pa.us>
To: "Michael Richards" <miker@interchange.ca>
Cc: <pgsql-hackers@postgresql.org>
Sent: Thursday, December 14, 2000 12:44 AM
Subject: Re: [HACKERS] (Updated) Table File Format


> "Michael Richards" <miker@interchange.ca> writes:
> >  Following that I find the 2 word tuple pointers.
> > The first word appears to be the offset in the page where the tuple can
be
> > found but the MSB has to be stripped off (haven't found it's function in
the
> > source yet).
> > The second is the transactionid that, if comitted gives this tuple
> > visibility???
>
> No, offset and length --- there is also a 2-bit flags field.  Look at
> the page and item declarations in src/include/storage/
>
> Someone else was recently working on a bit-level dump tool, but I've
> forgotten who.
>
> regards, tom lane



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