Thread: Questions

First,
Good luck to everyone.

I have a postgresql question.

My C function can run for a very very long time on some
inputs and reiterate on relations using SPI.
Basically, I open portals and cursors to relations
and use tuplestores. Also note that I always open the
relations in READ ONLY mode using SPI.

I have a great need to identify a tuple uniquely so
my prototype uses the CTID field for that purpose.

The question is, can the CTID field change throughout
the run of my function due to some other processes working
on the relation? Or because of command bounderies it is
pretty much secured inside an implicit transaction.
The problem wasn't so great if I didn't want to exploit
indices in the relations (but I do and does), since
after you issue a SELECT that uses indices, all you can rely on
is the CTID to uniquely identify a tuple.

The other solution is to temporarily duplicate the relations but
I don't like this very much.


Regards,
    Tzahi.
--
Tzahi Fadida
Blog: http://tzahi.blogsite.org | Home Site: http://tzahi.webhop.info
WARNING TO SPAMMERS:  see at http://members.lycos.co.uk/my2nis/spamwarning.html

Am Mittwoch, 31. Mai 2006 18:45 schrieb Tzahi Fadida:
> I have a postgresql question.

Please ask technical questions on one of the existing mailing lists.  This
mailing list is for coordinating student activitities, not as yet another
technical forum.

--
Peter Eisentraut
http://developer.postgresql.org/~petere/

Sorry, ok.
What about some infrastructure to post your code.
I have a working code and i want to start getting feedback.
In addition, it would be great to have some source versioning
system like cvs.
Can someone suggest a hosting solution?

regards,
    tzahi.

On Thu, 2006-06-01 at 09:34 +0200, Peter Eisentraut wrote:
> Am Mittwoch, 31. Mai 2006 18:45 schrieb Tzahi Fadida:
> > I have a postgresql question.
>
> Please ask technical questions on one of the existing mailing lists.  This
> mailing list is for coordinating student activitities, not as yet another
> technical forum.
>

Peter,

> Please ask technical questions on one of the existing mailing lists.  This
> mailing list is for coordinating student activitities, not as yet another
> technical forum.
>

Um, why not?   Weren't we just discussing on -Core how -Hackers has
become hard to approach?  I thought part of the idea behind this list
was to coordinate student activities ... technical *and* non-technical.

--Josh

Josh Berkus wrote:
> Um, why not?   Weren't we just discussing on -Core how -Hackers has
> become hard to approach?

Not to my knowledge.

> I thought part of the idea behind this list
> was to coordinate student activities ... technical *and*
> non-technical.

I don't know what the idea was, but if it's what you think I don't think
I will stay here.

--
Peter Eisentraut
http://developer.postgresql.org/~petere/

After All, should we post technical questions here or in the hackers?
I wanted some help :-)
Tom LLane said that there's already code in the backend for converting wal files into text. He also noted that would be a good idea to keep only one codebase for this.

So I was wondering, which functions are these? In which file can I find them?
I'm looking on backend/access/transam/xlog.c and backend/access/transam/xlogutils.c

But I'm feeling kind of lost... Somebody help me...




--
Diogo Biazus - diogob@gmail.com
Móvel Consultoria
http://www.movelinfo.com.br
http://www.postgresql.org.br

On 6/2/06, Diogo Biazus <diogob@gmail.com> wrote:
> Tom Lane said that there's already code in the backend for
> converting wal files into text. He also noted that would be
> a good idea to keep only one codebase for this.

Yep, I was talking to Bruce Momjian about this as well.  It would be
nice for not only your project, but also anyone else that wants to
read the xlog (like resetxlog in the -f case) if xlog were more
modularized.  I don't know if this could be considered part of your
project or not, but I bet Tom would have some suggestions one way or
another on modularizing xlog.


--
Jonah H. Harris, Software Architect | phone: 732.331.1300
EnterpriseDB Corporation            | fax: 732.331.1301
33 Wood Ave S, 2nd Floor            | jharris@enterprisedb.com
Iselin, New Jersey 08830            | http://www.enterprisedb.com/

Tom is subscribed here?
Or it would be better to post this questions on hackers?




--
Diogo Biazus - diogob@gmail.com
Móvel Consultoria
http://www.movelinfo.com.br
http://www.postgresql.org.br

On 6/2/06, Diogo Biazus <diogob@gmail.com> wrote:
> Tom is subscribed here?
> Or it would be better to post this questions on hackers?

I posed it on -hackers for ya... under the subject of "Modularize
XLOG"  Go ahead and add to it if you need to.


--
Jonah H. Harris, Software Architect | phone: 732.331.1300
EnterpriseDB Corporation            | fax: 732.331.1301
33 Wood Ave S, 2nd Floor            | jharris@enterprisedb.com
Iselin, New Jersey 08830            | http://www.enterprisedb.com/