"David Boreham" <[EMAIL PROTECTED]> wrote
>>
> I don't think your NT overlapped I/O code is quite right. At least
> I think it will issue reads at a high rate without waiting for any of them
> to complete. Beyond some point that has to give the kernel gut-rot.
>
[also with reply to Gavin] look up
On Mon, 28 Nov 2005, Qingqing Zhou wrote:
>
>
> On Mon, 28 Nov 2005, Gavin Sherry wrote:
> >
> > MySQL, Oracle and others implement read-ahead threads to simulate async IO
> > 'pre-fetching'.
>
> Due to my tests on Windows (using the attached program and change
> enable_aio=true), seems aio doesn'
Qingqing Zhou wrote:
On Mon, 28 Nov 2005, Gavin Sherry wrote:
MySQL, Oracle and others implement read-ahead threads to simulate async IO
'pre-fetching'.
Due to my tests on Windows (using the attached program and change
enable_aio=true), seems aio doesn't help as a separ
"David Boreham" <[EMAIL PROTECTED]> wrote
>
> BTW, I heard a long time ago that NTFS has quite fancy read-ahead, where
> it attempts to detect the application's access pattern including if it is
> reading sequentially and even if there is a 'stride' to the accesses when
> they're not contiguous.
On Mon, 28 Nov 2005, Gavin Sherry wrote:
>
> I didn't want to jump on list and waive my hands until I had something to
> show, but since Qingqing is looking at the issue I thought I better raise
> it.
>
Don't worry :-) I separate the logic into a standalone program in order to
let more people ca
On Mon, 28 Nov 2005, Gavin Sherry wrote:
>
> MySQL, Oracle and others implement read-ahead threads to simulate async IO
> 'pre-fetching'.
Due to my tests on Windows (using the attached program and change
enable_aio=true), seems aio doesn't help as a separate thread - but maybe
because my usage i
FYI, I've personally used Oracle 9.2.0.4's async IO on Linux and have seen several installations which make use of it also.
On 11/28/05, Gavin Sherry <[EMAIL PROTECTED]> wrote:
On Mon, 28 Nov 2005, Tom Lane wrote:> Gavin Sherry <[EMAIL PROTECTED]
> writes:> > I haven't had time to prototype wheth
On Mon, 28 Nov 2005, Mark Kirkwood wrote:
>
> Do these ideas require threads in principle? ISTM that there could be
> (additional) process(es) waiting to perform pre-fetching or async io,
> and we could use the usual IPC machinary to talk between them...
>
Right. I use threads because it is easy
Gavin Sherry wrote:
The paper I linked to seemed to suggest that they weren't using async IO
in 9.2 -- which is fairly old. I'm not sure why the authors didn't test
10g.
There have been async io type parameters in Oracle's init.ora files from
(at least) 8i (disk_async_io=true IIRC) - on Sol
On Mon, 28 Nov 2005, Tom Lane wrote:
> Gavin Sherry <[EMAIL PROTECTED]> writes:
> > I haven't had time to prototype whether we can easily implement async IO
>
> Just as with any suggestion to depend on threads, you are going to have
> to show results that border on astounding to have any chance of
The paper I linked to seemed to suggest that they weren't using async IO
in 9.2 -- which is fairly old. I'm not sure why the authors didn't test
10g.
.. ok, interesting. Did they say that Oracle
isn't using aio ?
I can't see that. They that Oracle has no more than one outstanding I
Tom Lane wrote:
Gavin Sherry <[EMAIL PROTECTED]> writes:
I haven't had time to prototype whether we can easily implement async IO
Just as with any suggestion to depend on threads, you are going to have
to show results that border on astounding to have any chance of getting
this in. Otherwis
On Mon, 28 Nov 2005, David Boreham wrote:
> Gavin Sherry wrote:
>
> > MySQL, Oracle and others implement read-ahead threads to simulate async IO
>
> I always believed that Oracle used async file I/O. Not that I've seen their
> code, but I'm fairly sure they funded the addition of kernel aio to Lin
Gavin Sherry wrote:
MySQL, Oracle and others implement read-ahead threads to simulate async IO
I always believed that Oracle used async file I/O. Not that I've seen their
code, but I'm fairly sure they funded the addition of kernel aio to Linux
a few years back.
ButOracle comes from a tim
Gavin Sherry <[EMAIL PROTECTED]> writes:
> I haven't had time to prototype whether we can easily implement async IO
Just as with any suggestion to depend on threads, you are going to have
to show results that border on astounding to have any chance of getting
this in. Otherwise the portability is
Qingqing,
I am considering add an "ice-broker scan thread" to accelerate PostgreSQL
sequential scan IO speed. The basic idea of this thread is just like the
"read-ahead" method, but the difference is this one does not read the
data
into shared buffer pool directly, instead, it reads the data i
On Mon, 28 Nov 2005, Qingqing Zhou wrote:
>
> I am considering add an "ice-broker scan thread" to accelerate PostgreSQL
> sequential scan IO speed. The basic idea of this thread is just like the
> "read-ahead" method, but the difference is this one does not read the data
> into shared buffer pool
Qingqing Zhou wrote:
I am considering add an "ice-broker scan thread" to accelerate PostgreSQL
sequential scan IO speed. The basic idea of this thread is just like the
"read-ahead" method, but the difference is this one does not read the data
into shared buffer pool directly, instead, it reads t
I am considering add an "ice-broker scan thread" to accelerate PostgreSQL
sequential scan IO speed. The basic idea of this thread is just like the
"read-ahead" method, but the difference is this one does not read the data
into shared buffer pool directly, instead, it reads the data into file
syste
Bruce Momjian writes:
> With the applied patch that checks an entire heap page with one lock, is
> there any advantage of considering this for index pages?
Done already (see bitmap index scans).
regards, tom lane
---(end of broadcast)-
With the applied patch that checks an entire heap page with one lock, is
there any advantage of considering this for index pages?
--
Bruce Momjian| http://candle.pha.pa.us
pgman@candle.pha.pa.us | (610) 359-1001
+ If your life is a hard drive, |
Atsushi Ogawa wrote:
> I am interested in a following item in TODO.
>
> o Allow an alias to be provided for the target table in
> UPDATE/DELETE
> This is not SQL-spec but many DBMSs allow it.
>
> I think that this functionality is useful for the migration from
> other RDBMS. However the SQL92
Tom Lane <[EMAIL PROTECTED]> writes:
> In particular, the executor knows that the outer subplan is parameterless
> and therefore should deliver the same results each time (modulo volatile
> functions of course), so after the first cycle it could know that there's no
> point in trying the early fe
On Sun, Nov 27, 2005 at 07:44:55PM +, Simon Riggs wrote:
> not have any unique indexes or row triggers. It should be possible to
> take advantage of this automatically when those requirements are met,
> without any new options. Just as it was with Seq Scans, this is worth
> about 10% reduction
"Jim C. Nasby" <[EMAIL PROTECTED]> writes:
> (What would be the profiler to use on FBSD?)
gprof should work fine.
regards, tom lane
---(end of broadcast)---
TIP 6: explain analyze is your friend
On Fri, Nov 25, 2005 at 10:20:11AM -0500, Tom Lane wrote:
> Qingqing Zhou <[EMAIL PROTECTED]> writes:
> > I can see your computer is really slow, so my theory is that since it is
> > easy to hold a running-slowly horse than a fast one, so my spinlock on a
> > 2.4G modern machine should takes relati
Greg Stark <[EMAIL PROTECTED]> writes:
> I suspect this is obvious but since you asked, there isn't any way to keep
> around the hash table and just reuse it repeatedly instead of having to rescan
> the data over and over is there?
We already do that when possible --- which it's not in the particu
I wrote:
> For a query like this, where the hash join is being done repeatedly,
> it might be useful for the executor itself to track how often each
> subplan has been seen to be empty.
I implemented a simple form of this, and it made 8.1 faster than 8.0
on the test case I was using. Give it a tr
Michael Glaesemann wrote:
>
> On Nov 24, 2005, at 21:21 , Marcus Engene wrote:
>
> > When we're having an alias discussion, I'd really like to see NVL
> > in postgres. Not because of porting from oracle as much as just
> > spelling that without the reference manual is completely impossible.
>
Christopher Kings-Lynne wrote:
> Hi,
>
> I notice we added CEILING() as an alias to CEIL() for compatibility. We
> also have POWER() for POW().
>
> I notice that MySQL uses TRUNCATE() and we only have TRUNC(). Is
> TRUNCATE actually spec compliant? Should we add TRUNCATE anyway for
I don't
Christopher Kings-Lynne wrote:
> Also, POW() is not documented here:
I think POW is just there for backward compatibility and people should
use POWER().
---
>
> http://www.postgresql.org/docs/8.1/interactive/functions-math
Added to TODO:
* Allow COMMENT ON to accept an expression rather than just a
string
---
Michael Glaesemann wrote:
> I've been trying to be better at documentation in general and have
> been trying to t
On Nov 28, 2005, at 4:13 PM, Tom Lane wrote:
Yeah, could be. Anyway it doesn't seem like we can learn much more
today. You might as well just zing the vacuumdb process and let
things get back to normal. If it happens again, we'd have reason
to dig deeper.
Final report [ and apologies to ha
Title: AW: Hashjoin startup strategy (was Re: [HACKERS] Getting different number of results when using hashjoin on/off)
If the query runs slow it will be not such a problem, but I was very concerned about other queries having this problem too - without knowing it. I've already rewritten the q
On Mon, 28 Nov 2005, Alvaro Herrera wrote:
Tom Lane wrote:
Michael Fuhr <[EMAIL PROTECTED]> writes:
Any problems with CVS or anonymous CVS since the work last evening?
The master CVS is fine, but I agree that the anonymous mirror doesn't
seem to be tracking it ...
Apparently the CVSup serv
"Mario Weilguni" <[EMAIL PROTECTED]> writes:
> Thanks for the quick response, I've tried the patch, but it did not work
> as expected. When I set enable_hashjoin to off, everything works as
> expected, but with hashjoin on I do not even get results anymore, CPU is
> going up to 100% and after 3 min
On Nov 28, 2005, at 1:46 PM, Tom Lane wrote:
James Robinson <[EMAIL PROTECTED]> writes:
backtrace of the sshd doesn't look good:
Stripped executable :-( ... you won't get much info there. What of
the client at the far end of the ssh connection? You should probably
assume that the blockage
cvsup back up and running ...
On Mon, 28 Nov 2005, Alvaro Herrera wrote:
Tom Lane wrote:
Michael Fuhr <[EMAIL PROTECTED]> writes:
Any problems with CVS or anonymous CVS since the work last evening?
The master CVS is fine, but I agree that the anonymous mirror doesn't
seem to be tracking it
James Robinson <[EMAIL PROTECTED]> writes:
> Given the other culprits in play are bash running a straightforward
> shellscript line with redirected output to a simple file on a non-
> full filesystem, I'm leaning more towards the odds that something
> related to the sshd + tcp/ip + ssh client
James Robinson <[EMAIL PROTECTED]> writes:
> backtrace of the sshd doesn't look good:
Stripped executable :-( ... you won't get much info there. What of
the client at the far end of the ssh connection? You should probably
assume that the blockage is there, rather than in a commonly used bit
of s
Yes. This is from a 8.0.3 (with slightly older and different data,
resulting in only 9 rows, but the rest is the same):
Index Scan using ben_uk3 on foo1 ben (cost=0.00..73867.23 rows=863
width=27) (actual time=38.591..501.839 rows=9 loops=1)
Filter: (subplan)
SubPlan
-> Hash Join (c
On Nov 28, 2005, at 12:00 PM, Tom Lane wrote:
Your next move is to look at the state of sshd
and whatever is running at the client end of the ssh tunnel.
backtrace of the sshd doesn't look good:
(gdb) bt
#0 0xe410 in ?? ()
#1 0xbfffdb48 in ?? ()
#2 0x080a1e28 in ?? ()
#3 0x080a1e78
Hello Tom,
Thanks for the quick response, I've tried the patch, but it did not work
as expected. When I set enable_hashjoin to off, everything works as
expected, but with hashjoin on I do not even get results anymore, CPU is
going up to 100% and after 3 minutes I cancelled the query (it normale
wo
Tom Lane wrote:
> Michael Fuhr <[EMAIL PROTECTED]> writes:
> > Any problems with CVS or anonymous CVS since the work last evening?
>
> The master CVS is fine, but I agree that the anonymous mirror doesn't
> seem to be tracking it ...
Apparently the CVSup server is down too. I wonder if the anon
Michael Fuhr <[EMAIL PROTECTED]> writes:
> Any problems with CVS or anonymous CVS since the work last evening?
The master CVS is fine, but I agree that the anonymous mirror doesn't
seem to be tracking it ...
regards, tom lane
---(end of broadcast)-
"Mario Weilguni" <[EMAIL PROTECTED]> writes:
> No, I'm using 8.1.0, and tried it on different machines, always the same
> results.
I see it, I think: the recent changes to avoid work when one or the
other side of the hash join is empty would exit the hash join leaving
a state that confused ExecRe
James Robinson <[EMAIL PROTECTED]> writes:
> On Nov 28, 2005, at 11:38 AM, Tom Lane wrote:
>> Can you get a similar backtrace from the vacuumdb process?
> OK:
> (gdb) bt
> #0 0xe410 in ?? ()
> #1 0xbfffe4f8 in ?? ()
> #2 0x0030 in ?? ()
> #3 0x08057b68 in ?? ()
> #4 0xb7e98533 in
On Nov 28, 2005, at 11:38 AM, Tom Lane wrote:
Can you get a similar backtrace from the vacuumdb process?
(Obviously,
give gdb the vacuumdb executable not the postgres one.)
OK:
(gdb) bt
#0 0xe410 in ?? ()
#1 0xbfffe4f8 in ?? ()
#2 0x0030 in ?? ()
#3 0x08057b68 in ?? ()
#4 0xb7e
James Robinson <[EMAIL PROTECTED]> writes:
> (gdb) bt
> #0 0xe410 in ?? ()
> #1 0xbfffd508 in ?? ()
> #2 0x082aef97 in PqSendBuffer ()
> #3 0xbfffd4f0 in ?? ()
> #4 0xb7ec03e1 in send () from /lib/tls/libc.so.6
> #5 0x08137d27 in secure_write ()
> #6 0x0813c2a7 in internal_flush ()
> #7
Here ya go -- BTW -- your guys support is the _best_. But you know
that already:
[EMAIL PROTECTED]:/home/sscadmin> gdb /usr/local/pgsql/bin/postgres 19244
GNU gdb 6.2.1
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and
you are
w
Thanks Tom for you quick answer!
No, I'm using 8.1.0, and tried it on different machines, always the same
results.
SELECT version();
PostgreSQL 8.1.0 on i686-pc-linux-gnu, compiled by GCC gcc (GCC) 3.3.4 20040623
(Gentoo Hardened Linux 3.3.4-r1, ssp-3.3.2-2, pie-8.7.6)
Best regards,
Ma
James Robinson <[EMAIL PROTECTED]> writes:
> As fate would have it, the vacuumdb frontend and backend which were
> initially afflicted are still in existence:
OK, so pid 19244 isn't blocked on any lmgr lock; else we'd see an entry
with granted = f for it in pg_locks. It could be blocked on a lo
As fate would have it, the vacuumdb frontend and backend which were
initially afflicted are still in existence:
sscadmin 19236 19235 0 Nov25 ?00:00:00 /usr/local/pgsql/bin/
vacuumdb -U postgres --all --analyze --verbose
postgres 19244 3596 0 Nov25 ?00:00:02 postgres: postgre
"Mario Weilguni" <[EMAIL PROTECTED]> writes:
> Yes. This is from a 8.0.3 (with slightly older and different data,
> resulting in only 9 rows, but the rest is the same):
Yeah, that looks more reasonable.
I tried to reproduce this, without any luck:
regression=# explain analyze select count(*) fro
Any problems with CVS or anonymous CVS since the work last evening?
Anonymous CVS hasn't given me the following commit yet; it's been
almost twelve hours since it was made:
http://archives.postgresql.org/pgsql-committers/2005-11/msg00553.php
--
Michael Fuhr
---(end of br
James Robinson <[EMAIL PROTECTED]> writes:
> Comparing the logs further with when it did complete, it seems that
> one table in particular (at least) seems afflicted:
> social=# vacuum verbose analyze agency.swlog_client;
> hangs up forever -- have to control-c the client. Likewise for w/o
>
G'day folks.
We have a production database running 8.0.3 which gets fully
pg_dump'd and vacuum analyze'd hourly by cron. Something strange
happened to us on the 5AM Friday Nov. 25'th cron run -- the:
/usr/local/pgsql/bin/vacuumdb -U postgres --all --analyze --verbose
>& $DATE/vacuum.log
Mario Weilguni <[EMAIL PROTECTED]> writes:
> The failing case is:
> ...
>SubPlan
> -> Hash Join (cost=8.47..19.46 rows=1 width=0) (actual
> time=0.004..0.004 rows=0 loops=21619)
>Hash Cond: ("outer".id = "inner".str_id)
>-> Bitmap Heap Scan on structure str (co
Andrew Dunstan <[EMAIL PROTECTED]> writes:
> First, do not name the mailing list in both the To: and Cc: lines -
> that's just redundant. Second, this is the wrong list to ask this
> question, as you were told last time. Ask on the pgsql-general list.
And third, show us the darn error messages .
First, do not name the mailing list in both the To: and Cc: lines -
that's just redundant. Second, this is the wrong list to ask this
question, as you were told last time. Ask on the pgsql-general list.
cheers
andrew
R, Rajesh (STSD) wrote:
PLZ REPLY
Hello there,
I run Postgresql 8.0.3
PLZ REPLY
Hello there,
I run Postgresql 8.0.3 on Tru64 Unix m/c.
I have included the ipv6 auth. line in my pg_hba.conf file(::1/128) I
keep getting error msgs from postmaster everytime I try to connect.
Going by previous posts on the topic am unable to conclude.
Does this mean pg 8.0.3 doesn'
Alvaro Herrera <[EMAIL PROTECTED]> writes:
> I don't see why couldn't have an additional index access method entry
> point to insert multiple rows on one call.
I think Simon was mainly on about the idea of inserting multiple *heap*
entries with one call, ie, only one cycle of locking a heap buffer
I am interested in a following item in TODO.
o Allow an alias to be provided for the target table in
UPDATE/DELETE
This is not SQL-spec but many DBMSs allow it.
I think that this functionality is useful for the migration from
other RDBMS. However the SQL92 spec does not allow an alias for
the
Hi,
Is there something weird going on with the lists?
I ask because lately there has been spam showing up rather frequently,
something that happenned only very ocassionally. Has there been a
change from human moderation to robotical approval of messages?
Also, my last auto-mails to pgsql-commit
Am Montag, 28. November 2005 14:12 schrieb Christopher Kings-Lynne:
> > The path field is an "ltree" column, with an GIST index on it.
>
> Something to do with bitmap indexscans on lossy indexes?
>
> Chris
I doubt that, "set enable_bitmapscan to off" produces the wrong result as
well.
Best regar
The path field is an "ltree" column, with an GIST index on it.
Something to do with bitmap indexscans on lossy indexes?
Chris
---(end of broadcast)---
TIP 2: Don't 'kill -9' the postmaster
I've a problem that might be a bug in the core system (hashjoins) or with ltree
using gist-index, but I fail miserable to produce a useful testcase (using 8.1,
worked in 8.0):
A query produces wrong (=0) results, when a different plan is enforced, I get a
merge-join plan that looks similar, but
On Mon, Nov 28, 2005 at 09:39:36AM +, Simon Riggs wrote:
> On Mon, 2005-11-28 at 09:40 +0100, Martijn van Oosterhout wrote:
> > Whatever happened to that idea to build as entire datafile with COPY or
> > some external tool and simply copy it into place and update the
> > catalog?
>
> What's wr
On Mon, 2005-11-28 at 00:56 +, Simon Riggs wrote:
> On Sun, 2005-11-27 at 17:45 -0500, Tom Lane wrote:
> > Simon Riggs <[EMAIL PROTECTED]> writes:
> > > COPY FROM can read in sufficient rows until it has a whole block worth
> > > of data, then get a new block and write it all with one pair of
>
Simon Riggs wrote:
> On Sun, 2005-11-27 at 17:45 -0500, Tom Lane wrote:
> > Simon Riggs <[EMAIL PROTECTED]> writes:
> > > COPY FROM can read in sufficient rows until it has a whole block worth
> > > of data, then get a new block and write it all with one pair of
> > > BufferLock calls.
> >
> > > C
On Sun, 2005-11-27 at 17:45 -0500, Tom Lane wrote:
> Simon Riggs <[EMAIL PROTECTED]> writes:
> > COPY FROM can read in sufficient rows until it has a whole block worth
> > of data, then get a new block and write it all with one pair of
> > BufferLock calls.
>
> > Comments?
>
> I don't see any way
http://acronymfinder.com/
Cheers,
Csaba.
On Fri, 2005-11-25 at 19:24, Gustavo Tonini wrote:
> What is "ISTM"?
>
> Sorry,
> Gustavo.
---(end of broadcast)---
TIP 9: In versions below 8.0, the planner will ignore your desire to
choose an ind
On Mon, 2005-11-28 at 09:40 +0100, Martijn van Oosterhout wrote:
> On Sun, Nov 27, 2005 at 05:45:31PM -0500, Tom Lane wrote:
> > Simon Riggs <[EMAIL PROTECTED]> writes:
> > > COPY FROM can read in sufficient rows until it has a whole block worth
> > > of data, then get a new block and write it all
On Sun, Nov 27, 2005 at 05:45:31PM -0500, Tom Lane wrote:
> Simon Riggs <[EMAIL PROTECTED]> writes:
> > COPY FROM can read in sufficient rows until it has a whole block worth
> > of data, then get a new block and write it all with one pair of
> > BufferLock calls.
>
> > Comments?
>
> I don't see
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