Hi,
Please find my answers inline
Do you have evidence of that contention being so worse, that it
justifies the additional WAL reading from disk? (Assuming no WAL
archiving).
On a broader sense, DSM is a bitmap index with some optimization that has
been placed to make the updates more
One more application of the same is Asynchronous Materialized views. I hope
you agree that the asynchronous materialized views have to get updated only
through WAL. If WAL can be used for that purpose, why can't we multiplex it?
Thanks,
Gokul.
Well, one of the principal arguments for having VACUUM at all is that it
off-loads required maintenance effort from foreground transaction code
paths. I'm not really going to be in favor of solutions that put more
work into the transaction code paths (HOT already did more of that than
I
There is absolutely 0 value in tackling that until someone can fix
hash's performance problems. If there is no real-world scenario for
using it ... which there really isn't ... then adding WAL support
still leaves you with no real-world scenario for using it.
This is not to suggest that I
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Bruce Momjian wrote:
An array subscript expression will return null if either the array itself
or any of the subscript expressions are null. Also, null is returned
if a subscript is outside the array bounds (this case does not raise an
Am Donnerstag, 10. Januar 2008 schrieb Roberts, Jon:
On PostgreSQL:
select to_date('31-DEC-200700:00:00', 'dd-mon- hh24:mi:ss');
to_date
--
200700-12-31
Oracle removes all white spaces in the date you pass in and the date
format.
I don't have a strong opinion on
Merlin Moncure wrote:
On Jan 12, 2008 4:19 PM, Simon Riggs [EMAIL PROTECTED] wrote:
On Sat, 2008-01-12 at 13:27 +0100, Jean-Michel Pouré wrote:
Please pick-up this important issue for developpers. There is no need to
concentrate on complex issues, when handling materialized views could
boost
Gokulakannan Somasundaram wrote:
Well, one of the principal arguments for having VACUUM at all is that it
off-loads required maintenance effort from foreground transaction code
paths. I'm not really going to be in favor of solutions that put more
work into the transaction code paths (HOT
Personally I find the automatic partition idea intriguing, where you
only have to choose an expression that equates to one value (value
group) per partition (and possibly a way to derive a
partition name).
IMO, better go right to a fully automated approach. Or why would you
need
D'Arcy J.M. Cain wrote:
On Tue, 15 Jan 2008 16:11:16 -0600
Roberts, Jon [EMAIL PROTECTED] wrote:
I need to set a basic password policy for accounts but I don't see any
documentation on how to do it. I'm assuming there is a way to do this,
maybe even with a trigger.
The policy would be
Heikki Linnakangas escribió:
Another issue is that reading WAL is inherently not very scalable. There's
only one WAL for the whole cluster, and it needs to be read sequentially,
so it can easily become a bottleneck on large systems.
I have wondered why do we do it this way. Is there a
Hi,
I have submitted a new patch against thick indexes(indexes with snapshot)
http://archives.postgresql.org/pgsql-hackers/2007-10/msg00220.php.http://archives.postgresql.org/pgsql-hackers/2007-10/msg00220.php
I did look closely at improving the performance of count(1) queries. It
worked well,
I haven't been paying close attention to this thread, but there is a
couple general issues with using the WAL for this kind of things. First
of all, one extremely cool feature of PostgreSQL is that transaction
size is not limited by WAL space, unlike on many other DBMSs. I think
many of the
Peter Eisentraut [EMAIL PROTECTED] writes:
A further example shows that to_date seems to have little error checking
altogether:
Yeah, that's been one of the main knocks on that code since day one.
Somebody needs to spend a whole lot of time on it, and the original
author has left the project
On Tue, Jan 15, 2008 at 07:18:17PM -0800, John Smith wrote:
http://archives.postgresql.org/pgsql-hackers/2007-10/msg01468.php,
... I very much want to encourage authors of new Resource Managers and it
looks like we may be getting at least 3 new RMs that produce WAL
records: hash indexes
On Wed, 16 Jan 2008 08:32:12 -0500
Andrew Dunstan [EMAIL PROTECTED] wrote:
I need to set a basic password policy for accounts but I don't see any
Look at my chkpass type in contrib. There is a function to verify the
password. It is just a placeholder now but you can modify it to do all
Tom Lane wrote:
Chris Browne [EMAIL PROTECTED] writes:
Note that we required that the provider transaction have the
attributes IsXactIsoLevelSerializable and XactReadOnly both being
true, so we have the mandates that the resultant backend process:
a) Is in read only mode, and
b) Is in
-Original Message-
From: D'Arcy J.M. Cain [mailto:[EMAIL PROTECTED]
Sent: Wednesday, January 16, 2008 9:39 AM
To: Andrew Dunstan
Cc: Roberts, Jon; pgsql-hackers@postgresql.org
Subject: Re: [HACKERS] Password policy
On Wed, 16 Jan 2008 08:32:12 -0500
Andrew Dunstan [EMAIL
Alvaro Herrera [EMAIL PROTECTED] writes:
Heikki Linnakangas escribió:
Another issue is that reading WAL is inherently not very scalable. There's
only one WAL for the whole cluster, and it needs to be read sequentially,
so it can easily become a bottleneck on large systems.
I have wondered
Tom Lane escribió:
Alvaro Herrera [EMAIL PROTECTED] writes:
Heikki Linnakangas escribi�:
Another issue is that reading WAL is inherently not very scalable. There's
only one WAL for the whole cluster, and it needs to be read sequentially,
so it can easily become a bottleneck on large
Here (@sophos.com) we run machine cluster tests using FreeBSD jails. A
jail is halfway between a chroot and a VM. Jails blow a number of
assumptions about a unix environment: sysv ipc's are global to all
jails; but a process can only see other processes also running in the
jail. In fact, the
Florian G. Pflug [EMAIL PROTECTED] writes:
I seem to remember there being some pushback to the idea of changing the
semantics of set transaction isolation read only from soft to hard
semantics though - on the basis that it might break existing
applications. If that has changed (or my memory
Alvaro Herrera [EMAIL PROTECTED] writes:
Tom Lane escribió:
It would only be useful to have one per spindle-dedicated-to-WAL, so
tying the division to databases doesn't seem like it'd be a good idea.
Keep in mind that there are claims that a write-cache-enabled
battery-backed RAID
Tom Lane wrote:
Peter Eisentraut [EMAIL PROTECTED] writes:
A further example shows that to_date seems to have little error checking
altogether:
Yeah, that's been one of the main knocks on that code since day one.
Somebody needs to spend a whole lot of time on it, and the original
Mischa Sandberg [EMAIL PROTECTED] writes:
+ /* In a FreeBSD jail, you can't kill -0 a postmaster
+* running in a different jail, so the shm seg might
+* still be in use. Safer to test nattch ?
+*/
+ if (kill(1,0)
Tom Lane escribió:
Alvaro Herrera [EMAIL PROTECTED] writes:
Tom Lane escribió:
It would only be useful to have one per spindle-dedicated-to-WAL, so
tying the division to databases doesn't seem like it'd be a good idea.
Keep in mind that there are claims that a write-cache-enabled
Quoting Tom Lane [EMAIL PROTECTED]:
Mischa Sandberg [EMAIL PROTECTED] writes:
+ /* In a FreeBSD jail, you can't kill -0 a
postmaster
+* running in a different jail, so the shm seg
might
+* still be in use. Safer to test nattch ?
+
Tom Lane [EMAIL PROTECTED] writes:
Alvaro Herrera [EMAIL PROTECTED] writes:
Heikki Linnakangas escribió:
Another issue is that reading WAL is inherently not very scalable. There's
only one WAL for the whole cluster, and it needs to be read sequentially,
so it can easily become a bottleneck
On Jan 16, 2008 6:12 PM, Alvaro Herrera [EMAIL PROTECTED] wrote:
Tom Lane escribió:
Possibly true, but if that's the underlying hardware then there's no
performance benefit in breaking WAL up at all, no?
Selective PITR shipping.
If it was possible to launch a PITR only on a given database,
Mischa Sandberg [EMAIL PROTECTED] writes:
Quoting Tom Lane [EMAIL PROTECTED]:
Mischa Sandberg [EMAIL PROTECTED] writes:
+ if (kill(1,0) errno == ESRCH
PGSharedMemoryIsInUse(0,NextShmemSegID))
+ continue;
Isn't the last part of that test backward? If
On Wed, 16 Jan 2008, Alvaro Herrera wrote:
Keep in mind that there are claims that a write-cache-enabled
battery-backed RAID controller negates the effect of a separate spindle.
Negates is a bit strong; there's still some performance advantage on
systems that write a serious amount of data.
* Mischa Sandberg ([EMAIL PROTECTED]) wrote:
Here (@sophos.com) we run machine cluster tests using FreeBSD jails. A
jail is halfway between a chroot and a VM. Jails blow a number of
assumptions about a unix environment: sysv ipc's are global to all
jails; but a process can only see other
On Wed, Jan 16, 2008 at 11:40 AM, in message
[EMAIL PROTECTED], Greg Smith
[EMAIL PROTECTED] wrote:
On Wed, 16 Jan 2008, Alvaro Herrera wrote:
Keep in mind that there are claims that a write-cache-enabled
battery-backed RAID controller negates the effect of a separate spindle.
Negates is
Guillaume Smet wrote:
On Jan 16, 2008 6:12 PM, Alvaro Herrera [EMAIL PROTECTED] wrote:
Tom Lane escribió:
Possibly true, but if that's the underlying hardware then there's no
performance benefit in breaking WAL up at all, no?
Selective PITR shipping.
If it was possible to launch a PITR only
For more usefulness, we'd need to keep databases more separate from each
other than we do now. Databases would need to have their own transaction
counters, for example. Shared relations would obviously need major
changes for that to work. If we ultimately could separate databases so
that
On Jan 16, 2008 7:41 PM, Heikki Linnakangas [EMAIL PROTECTED] wrote:
I don't think it's going to work too well, though, not without major
changes at least.
Well, I know it's really not doable with the current behaviour of WAL.
I just wanted to point this feature request because we had it a few
Tom Lane wrote:
Andrew Dunstan [EMAIL PROTECTED] writes:
In helping someome on IRC it has become apparent that unless I am
mistaken COPY foo from 'filename' is reading the file according to the
client encoding.
Is that the expected behaviour?
Yes, it is. Not sure if
Stephen Frost [EMAIL PROTECTED] writes:
I've got a couple of concerns about this-
#1: Having the shared memory be global is a rather large problem when it
comes to something like PG which can have a fair bit of data going
through that area that could be sensitive.
Well, you'd have
Heikki Linnakangas escribió:
I don't think it's going to work too well, though, not without major
changes at least. What would happen when you restore a PITR backup of just
one database? Would the other databases still be there in the restored
cluster? What state would they be in? After
Alvaro Herrera wrote:
Heikki Linnakangas escribió:
For more usefulness, we'd need to keep databases more separate from each
other than we do now. Databases would need to have their own transaction
counters, for example.
Hmm, why? Perhaps you are right but I don't see the reason.
If each
Just to conclude on the issue we had here.
As far as I can see, the ulimits are set up as they should; and on a
64-bit machine with 16GB RAM, I don't see there should be a problem with
allocating 2 GB maintenance work memory. In any case, I have serious
difficulty believing that the ulimits can
On Wed, 16 Jan 2008, Kevin Grittner wrote:
I haven't seen any benchmarks on the list or in our environment
where the separate spindles gave more than a 1% increase in
performance when using a good-quality BBC controller.
Well, even 1% isn't nothing, which is the main point I was making--it
Andrew Dunstan wrote:
Tom Lane wrote:
Peter Eisentraut [EMAIL PROTECTED] writes:
A further example shows that to_date seems to have little error checking
altogether:
Yeah, that's been one of the main knocks on that code since day one.
Somebody needs to spend a whole
Andrew Dunstan [EMAIL PROTECTED] writes:
Tom Lane wrote:
Yes, it is. Not sure if it's adequately documented.
Will this cover the case?
Text looks OK. I think it might fit better a bit further up, adjacent
to the para about DateStyle which is a somewhat comparable
consideration.
Peter Eisentraut wrote:
Am Donnerstag, 10. Januar 2008 schrieb Roberts, Jon:
On PostgreSQL:
select to_date('31-DEC-200700:00:00', 'dd-mon- hh24:mi:ss');
to_date
--
200700-12-31
Oracle removes all white spaces in the date you pass in and the date
format.
On Wed, 2008-01-16 at 11:16 +, Heikki Linnakangas wrote:
Merlin Moncure wrote:
On Jan 12, 2008 4:19 PM, Simon Riggs [EMAIL PROTECTED] wrote:
On Sat, 2008-01-12 at 13:27 +0100, Jean-Michel Pouré wrote:
Please pick-up this important issue for developpers. There is no need to
On Wed, 2008-01-16 at 21:53 +0100, Michael Omotayo Akinde wrote:
As far as I can see, the ulimits are set up as they should; and on a
64-bit machine with 16GB RAM, I don't see there should be a problem
with allocating 2 GB maintenance work memory. In any case, I have
serious difficulty
Tom Lane wrote:
There was some discussion last week on -bugs about how renaming an index
that belongs to a unique or primary key constraint is allowed, but can
lead to situations that can't be dumped/restored properly. This isn't
really pg_dump's fault, IMHO. We should rather make the
Simon Riggs wrote:
My thinking was if you load a 1000 rows and they all have the same key
in your summary table then you'll be doing 1000 updates on a single row.
This is true because the statement level triggers are still rudimentary,
with no OLD and NEW support. A single AFTER statement
[EMAIL PROTECTED] (Mischa Sandberg) writes:
Unfortunately, with multiple jails running PG servers and (due to app
limitations) all servers having same PGPORT, you get the situation that
when jail#2 (,jail#3,...) server comes up, it:
- detects that there is a shm seg with ipc key 5432001
- checks
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- --On Thursday, January 17, 2008 01:12:54 -0500 Tom Lane [EMAIL PROTECTED]
wrote:
Marc G. Fournier [EMAIL PROTECTED] writes:
[EMAIL PROTECTED] (Mischa Sandberg) writes:
Unfortunately, with multiple jails running PG servers and (due to app
Marc G. Fournier [EMAIL PROTECTED] writes:
[EMAIL PROTECTED] (Mischa Sandberg) writes:
Unfortunately, with multiple jails running PG servers and (due to app
limitations) all servers having same PGPORT, you get the situation that
when jail#2 (,jail#3,...) server comes up, it:
- detects that
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