hi,

we are running Postgres 7.3.3 successfully on our portal sites
under Solaris. For a new project we have the requirement that
N processes need to write update/insert within the same time and within
the same transaction data in one table. More detailed: every process
opens its own connection, starts a transaction, updates *different* rows
and then commits. According to our postgres adminstrator, Postgres seems
to behave differently on Linux and Solaris. Any ideas on that?

Thanks,
Andreas



29 Jul 2003 12:33:06 +0200
Andreas Jung <andreas.jung@haufe.de>
concurrent writes
On 29 Jul 2003 at 12:33, Andreas Jung wrote:
> we are running Postgres 7.3.3 successfully on our portal sites
> under Solaris. For a new project we have the requirement that
> N processes need to write update/insert within the same time and within
> the same transaction data in one table. 

What does it mean by same transaction data?


>More detailed: every process
> opens its own connection, starts a transaction, updates *different* rows
> and then commits. According to our postgres adminstrator, Postgres seems
> to behave differently on Linux and Solaris. Any ideas on that?

How it is different? It should be same, right?

Bye
 Shridhar

--
QOTD:	"I may not be able to walk, but I drive from the sitting posistion."


Tue, 29 Jul 2003 16:12:24 +0530
"Shridhar Daithankar" <shridhar_daithankar@persistent.co.in>
Re: concurrent writes
On Tue, 2003-07-29 at 12:42, Shridhar Daithankar wrote:
> On 29 Jul 2003 at 12:33, Andreas Jung wrote:
> > we are running Postgres 7.3.3 successfully on our portal sites
> > under Solaris. For a new project we have the requirement that
> > N processes need to write update/insert within the same time and within
> > the same transaction data in one table. 
> 
> What does it mean by same transaction data?

should read "update/insert within the same time and within the same
transaction in one table"

> 
> 
> >More detailed: every process
> > opens its own connection, starts a transaction, updates *different* rows
> > and then commits. According to our postgres adminstrator, Postgres seems
> > to behave differently on Linux and Solaris. Any ideas on that?
> 
> How it is different? It should be same, right?

Our experience was that the complete table has been locked (Solaris)
but row-level locking was working with Linux.

-aj



29 Jul 2003 12:48:35 +0200
Andreas Jung <andreas.jung@haufe.de>
Re: concurrent writes
On 29 Jul 2003 at 12:48, Andreas Jung wrote:

> On Tue, 2003-07-29 at 12:42, Shridhar Daithankar wrote:
> > On 29 Jul 2003 at 12:33, Andreas Jung wrote:
> > > we are running Postgres 7.3.3 successfully on our portal sites
> > > under Solaris. For a new project we have the requirement that
> > > N processes need to write update/insert within the same time and within
> > > the same transaction data in one table. 
> > 
> > What does it mean by same transaction data?
> 
> should read "update/insert within the same time and within the same
> transaction in one table"

So you want to update same table more than once in a single transaction? That 
should work..

> > >More detailed: every process
> > > opens its own connection, starts a transaction, updates *different* rows
> > > and then commits. According to our postgres adminstrator, Postgres seems
> > > to behave differently on Linux and Solaris. Any ideas on that?
> > 
> > How it is different? It should be same, right?
> 
> Our experience was that the complete table has been locked (Solaris)
> but row-level locking was working with Linux.

Whoa!! That's something. How did you conclude it is locked. If you can produce 
some reproducible test case, this would be a big showstopper bug..


		
Bye
 Shridhar

--
flannister, n.:	The plastic yoke that holds a six-pack of beer together.		-- 
"Sniglets", Rich Hall & Friends


Tue, 29 Jul 2003 16:32:54 +0530
"Shridhar Daithankar" <shridhar_daithankar@persistent.co.in>
Re: concurrent writes
On Tue, 2003-07-29 at 13:02, Shridhar Daithankar wrote:
> On 29 Jul 2003 at 12:48, Andreas Jung wrote:
> 
> > On Tue, 2003-07-29 at 12:42, Shridhar Daithankar wrote:
> > > On 29 Jul 2003 at 12:33, Andreas Jung wrote:
> > > > we are running Postgres 7.3.3 successfully on our portal sites
> > > > under Solaris. For a new project we have the requirement that
> > > > N processes need to write update/insert within the same time and within
> > > > the same transaction data in one table. 
> > > 
> > > What does it mean by same transaction data?
> > 
> > should read "update/insert within the same time and within the same
> > transaction in one table"
> 
> So you want to update same table more than once in a single transaction? That 
> should work..
> 
> > > >More detailed: every process
> > > > opens its own connection, starts a transaction, updates *different* rows
> > > > and then commits. According to our postgres adminstrator, Postgres seems
> > > > to behave differently on Linux and Solaris. Any ideas on that?
> > > 
> > > How it is different? It should be same, right?
> > 
> > Our experience was that the complete table has been locked (Solaris)
> > but row-level locking was working with Linux.
> 
> Whoa!! That's something. How did you conclude it is locked. If you can produce 
> some reproducible test case, this would be a big showstopper bug..
> 

This problem appeard in 7.3.2 but it seems to have been fixed in 7.3.3.
Our administrator complained that there has not been a notice in the
CHANGELOG...so I am hestitating about choosing Postgres vs. Oracle :-)

-aj



29 Jul 2003 13:07:57 +0200
Andreas Jung <andreas.jung@haufe.de>
Re: concurrent writes
On 29 Jul 2003 at 13:07, Andreas Jung wrote:

> On Tue, 2003-07-29 at 13:02, Shridhar Daithankar wrote:
> > On 29 Jul 2003 at 12:48, Andreas Jung wrote:
> > > Our experience was that the complete table has been locked (Solaris)
> > > but row-level locking was working with Linux.
> > 
> > Whoa!! That's something. How did you conclude it is locked. If you can produce 
> > some reproducible test case, this would be a big showstopper bug..
> > 
> 
> This problem appeard in 7.3.2 but it seems to have been fixed in 7.3.3.
> Our administrator complained that there has not been a notice in the
> CHANGELOG...so I am hestitating about choosing Postgres vs. Oracle :-)

Even with 7.3.2, do you have a independently reproducible test case? It should 
help hackers to look into it.

Bye
 Shridhar

--
Matz's Law:	A conclusion is the place where you got tired of thinking.


Tue, 29 Jul 2003 16:46:35 +0530
"Shridhar Daithankar" <shridhar_daithankar@persistent.co.in>
Re: concurrent writes
On Tue, 2003-07-29 at 13:16, Shridhar Daithankar wrote:
> On 29 Jul 2003 at 13:07, Andreas Jung wrote:
> 
> > On Tue, 2003-07-29 at 13:02, Shridhar Daithankar wrote:
> > > On 29 Jul 2003 at 12:48, Andreas Jung wrote:
> > > > Our experience was that the complete table has been locked (Solaris)
> > > > but row-level locking was working with Linux.
> > > 
> > > Whoa!! That's something. How did you conclude it is locked. If you can produce 
> > > some reproducible test case, this would be a big showstopper bug..
> > > 
> > 
> > This problem appeard in 7.3.2 but it seems to have been fixed in 7.3.3.
> > Our administrator complained that there has not been a notice in the
> > CHANGELOG...so I am hestitating about choosing Postgres vs. Oracle :-)
> 
> Even with 7.3.2, do you have a independently reproducible test case? It should 
> help hackers to look into it.
> 

I need to ask our postgres god and let you know.

Andreas


29 Jul 2003 13:21:45 +0200
Andreas Jung <andreas.jung@haufe.de>
Re: concurrent writes
On Tue, 2003-07-29 at 05:48, Andreas Jung wrote:
> On Tue, 2003-07-29 at 12:42, Shridhar Daithankar wrote:
> > On 29 Jul 2003 at 12:33, Andreas Jung wrote:
> > > we are running Postgres 7.3.3 successfully on our portal sites
> > > under Solaris. For a new project we have the requirement that
> > > N processes need to write update/insert within the same time and within
> > > the same transaction data in one table. 
> > 
> > What does it mean by same transaction data?
> 
> should read "update/insert within the same time and within the same
> transaction in one table"

How can N number of transactions write into the database, all within
the *same* transaction?

-- 
+-----------------------------------------------------------------+
| Ron Johnson, Jr.        Home: ron.l.johnson@cox.net             |
| Jefferson, LA  USA                                              |
|                                                                 |
| "I'm not a vegetarian because I love animals, I'm a vegetarian  |
|  because I hate vegetables!"                                    |
|    unknown                                                      |
+-----------------------------------------------------------------+



29 Jul 2003 09:19:06 -0500
Ron Johnson <ron.l.johnson@cox.net>
Re: concurrent writes
Andreas Jung <andreas.jung@haufe.de> writes:
> On Tue, 2003-07-29 at 13:02, Shridhar Daithankar wrote:
>>> Our experience was that the complete table has been locked (Solaris)
>>> but row-level locking was working with Linux.
>> 
>> Whoa!! That's something. How did you conclude it is locked. If you can produce 
>> some reproducible test case, this would be a big showstopper bug..

> This problem appeard in 7.3.2 but it seems to have been fixed in 7.3.3.
> Our administrator complained that there has not been a notice in the
> CHANGELOG.

That's because there was no such fix.  I'd be interested to see your
test case.

			regards, tom lane

Tue, 29 Jul 2003 10:57:18 -0400
Tom Lane <tgl@sss.pgh.pa.us>
Re: concurrent writes 
If I understand your idea, and Postgres, this is like saying you want multiple backend processes, and definite, "NO". As far as I know, one connection == 1 xaction.

Andreas Jung wrote:
> hi,
> 
> we are running Postgres 7.3.3 successfully on our portal sites
> under Solaris. For a new project we have the requirement that
> N processes need to write update/insert within the same time and within
> the same transaction data in one table. More detailed: every process
> opens its own connection, starts a transaction, updates *different* rows
> and then commits. According to our postgres adminstrator, Postgres seems
> to behave differently on Linux and Solaris. Any ideas on that?
> 
> Thanks,
> Andreas
> 
> 
> 
> ---------------------------(end of broadcast)---------------------------
> TIP 5: Have you checked our extensive FAQ?
> 
>                http://www.postgresql.org/docs/faqs/FAQ.html
> 


Tue, 29 Jul 2003 08:30:00 -0700
Dennis Gearon <gearond@cvc.net>
Re: concurrent writes
On Tue, Jul 29, 2003 at 12:33:06PM +0200, Andreas Jung wrote:
> hi,
> 
> we are running Postgres 7.3.3 successfully on our portal sites

There's a nasty bug in 7.3.3 which is fixed in 7.3.4.

> N processes need to write update/insert within the same time and within
> the same transaction data in one table. More detailed: every process
> opens its own connection, starts a transaction, updates *different* rows
> and then commits. 

These two descriptions are not of the same thing.  Different
processes cannot share the same transaction, unless they're using the
same connection.

> According to our postgres adminstrator, Postgres seems
> to behave differently on Linux and Solaris. Any ideas on that?

Differently how?  Start up time for a connection is sure worse:
fork() on Solaris is slow as my dog with his foot in a bandage.

A

-- 
----
Andrew Sullivan                         204-4141 Yonge Street
Liberty RMS                           Toronto, Ontario Canada
<andrew@libertyrms.info>                              M2P 2A8
                                         +1 416 646 3304 x110


Tue, 29 Jul 2003 13:01:32 -0400
Andrew Sullivan <andrew@libertyrms.info>
Re: concurrent writes
On Tue, Jul 29, 2003 at 01:07:57PM +0200, Andreas Jung wrote:
> 
> This problem appeard in 7.3.2 but it seems to have been fixed in 7.3.3.
> Our administrator complained that there has not been a notice in the
> CHANGELOG...so I am hestitating about choosing Postgres vs. Oracle :-)

I think your administrator is talking out of his hat.  We switch back
and forth between Linux and Solaris all the time here, and PostgreSQL
works the same all the time.

A

-- 
----
Andrew Sullivan                         204-4141 Yonge Street
Liberty RMS                           Toronto, Ontario Canada
<andrew@libertyrms.info>                              M2P 2A8
                                         +1 416 646 3304 x110


Tue, 29 Jul 2003 13:02:44 -0400
Andrew Sullivan <andrew@libertyrms.info>
Re: concurrent writes