Hi,
Is it viable to have very many prepared transactions? As in tens of
thousands or even more?
The idea is so that a web application can do _persistent_
transactional stuff over multiple pages/accesses/sessions and have it
rolled back easily, or committed if desired. I'm thinking that it
At 04:27 PM 1/20/2012, Florian Weimer wrote:
* Lincoln Yeoh:
If you use serializable transactions in PostgreSQL 9.1, you can
implement such constraints in the application without additional
locking. However, with concurrent writes and without an index, the rate
of detected serialization
At 10:54 PM 1/19/2012, Florian Weimer wrote:
* Gnanakumar:
Just create a unique index on EMAIL column and handle error if it comes
Thanks for your suggestion. Of course, I do understand that this could be
enforced/imposed at the database-level at any time. But I'm trying to find
out
At 11:44 PM 10/17/2011, Tom Lane wrote:
Alban Hertroys haram...@gmail.com writes:
On 17 October 2011 17:25, Steve Crawford
scrawf...@pinpointresearch.com wrote:
Even stand-alone statements take place within a transaction - just not an
explicit one.
I doubt that more than 2.368 ms passed
At 03:51 AM 9/8/2011, Merlin Moncure wrote:
yeah -- but you only need to block selects if you are selecting in the
inserting transaction (this is not a full upsert). if both writers
are doing:
begin;
lock table foo exclusive;
insert into foo select ... where ...;
commit;
is good enough. btw
At 03:51 AM 9/8/2011, Merlin Moncure wrote:
Don't you have to block SELECTs so that the SELECTs get serialized?
Otherwise concurrent SELECTs can occur at the same time, find no existing
rows, then all the inserts proceed and you get errors (or dupes).
That's how Postgresql still works
At 04:04 AM 9/8/2011, Andrew Sullivan wrote:
On Wed, Sep 07, 2011 at 02:51:32PM -0500, Merlin Moncure wrote:
@andrew s: going SERIALIZABLE doesn't help if you trying to eliminate
cases that would push you into retrying the transaction.
Well, no, of course. But why not catch the failure and
At 05:23 AM 9/7/2011, Merlin Moncure wrote:
On Tue, Sep 6, 2011 at 3:45 PM, Merlin Moncure mmonc...@gmail.com wrote:
b) doesn't block reads if you lock in EXCLUSIVE mode. a) is the best
way to go if you prefer to handle errors on the client and/or
concurrency is important...c) otherwise.
At 07:02 PM 9/5/2011, J. Hondius wrote:
I agree that there are better ways to do this.
But for me this works. (legacy driven situation)
INSERT INTO tbinitialisatie (col1, col2)
SELECT 'x', 'y'
FROM tbinitialisatie
WHERE not exists (select * from tbinitialisatie where col1 = 'x'
and col2 =
At 04:13 AM 6/20/2011, Alexander Farber wrote:
why add a begin/commit if I only
have SELECT statements
there (in the default mode) and
the data isn't critical to me
(just some player statistics and
notes by other players - i.e.
a statistic or note is ok to be lost
occasionally)?
If you're not
At 06:07 PM 4/14/2011, RadosÅaw Smogura wrote:
One thing you should care about is such called
write endurance - number of writes to one memory
region before it will be destroyed - if your SSD
driver do not have transparent allocation, then
you may destroy it really fast, because write of
At 12:24 PM 11/9/2010, Sandeep Srinivasa wrote:
There was an interesting post today on highscalability -
At 11:42 AM 10/25/2010, Mike Chamberlain wrote:
Has anyone implemented FTS in Chinese on PG? Â I
guess I need a Chinese ispell dictionary and
parser, neither of which I can find after a lot of googling.
I have a bounty on this question on Stackoverflow if anyone wants to claim it:
At 11:32 AM 10/9/2010, Craig Ringer wrote:
On 10/09/2010 05:30 AM, Carlos Mennens wrote:
I know that MySQL uses MyISAM storage engine by default and was just
trying to look on Google to try and see if I could understand what
storage engine does PostgreSQL use by default when I generate a
At 12:20 AM 9/25/2010, Scott Marlowe wrote:
On Fri, Sep 24, 2010 at 9:56 AM, Steve Atkins st...@blighty.com wrote:
Again, you'd need to run them on comparable hardware and tune
them both well.
Actually I'd argue that pgsql gets better hardware since you can spend
the money you'd spend on
At 07:55 PM 9/22/2010, Vick Khera wrote:
Here's how you do it: first, make sure you are not within a
transaction or other Pg activity. Get the socket's file handle from
the Pg connection handle. When you're ready to wait for a notify
event, just do a select() system call on that file handle
At 11:46 AM 8/24/2010, Craig Ringer wrote:
On 24/08/2010 11:06 AM, A.M. wrote:
On Aug 23, 2010, at 10:18 PM, Craig Ringer wrote:
On 08/24/2010 06:43 AM, Bruce Momjian wrote:
A.M. wrote:
There is a new pg_notify function in pgsql 9.0 but no pg_listen
equivalent? Why? It sure would be handy
At 05:44 AM 12/17/2009, Greg Smith wrote:
You've probably already found
http://wiki.postgresql.org/wiki/Why_PostgreSQL_Instead_of_MySQL:_Comparing_Reliability_and_Speed_in_2007
which was my long treatment of this topic (and overdue for an update).
The main thing I intended to put into such an
At 03:19 AM 12/19/2009, David Boreham wrote:
Lincoln Yeoh wrote:
It seems you currently can only control outbound traffic from an
interface, so you'd have to set stuff on both interfaces to shape
upstream and downstream - this is not so convenient in some network topologies.
This is more
At 11:28 AM 12/18/2009, Scott Marlowe wrote:
On Thu, Dec 17, 2009 at 7:51 PM, David Boreham david_l...@boreham.org wrote:
Scott Marlowe wrote:
I would recommend using a traffic shaping router (like the one built
into the linux kernel and controlled by tc / iptables) to simulate a
long
At 04:44 AM 6/4/2009, Jennifer Trey wrote:
No, I created a new DB, created a table, and did not even populate any data.
Running select count(*) from test
just now, still caused the 10-20 I/O-writes.
Not sure if this is the main problem, but by default windows will
write to the disk whenever
At 07:57 PM 4/14/2009, Richard Huxton wrote:
wstrzalka wrote:
Why PG sort's my data in case insensitive manner?
masterdb=# select name, setting from pg_settings WHERE name ilike 'lc
%';
name | setting
-+-
lc_collate | en_US.UTF-8
Because that's what
At 10:00 PM 3/17/2009, Harald Armin Massa wrote:
Merlin,
I agree though
that a single table approach is best unless 1) the table has to scale
to really, really large sizes or 2) there is a lot of churn on the
data (lots of bulk inserts and deletes).
while agreeing, an additional question:
At 12:05 AM 3/18/2009, Erik Jones wrote:
On Mar 17, 2009, at 4:47 AM, Craig Ringer wrote:
The question is: Which DBMS do you think is the best for this kind of
application? PostgreSQL or MySQL?
As you can imagine, PostgreSQL.
My main reasons are that in a proper transactional environment
At 09:42 PM 10/14/2008, you wrote:
Mikkel Høgh wrote:
On 14/10/2008, at 11.40, Ivan Sergio Borgonovo wrote:
That might be true, if the only demographic you
are looking for are professional DBAs, but if
you're looking to attract more developers, not
having sensible defaults is not really a
At 10:30 PM 6/24/2008, David Siebert wrote:
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1
Which disto is best for running a Postgres server?
I just installed OpenSuse and downloaded and compiled the latest version
of Postgres. It isn't that big of a hassle but I noticed that almost
none of the
At 01:48 AM 5/13/2008, Justin wrote:
I have very annoying problem that i would like to get a work
around in place so the data entry people stop trying to kill me.
Normally people give quotes out of the price book which was done in
Excel like 15 years ago and just has been updated over the
At 04:46 AM 4/16/2008, Colin Wetherbee wrote:
Tom Lane wrote:
Colin Wetherbee [EMAIL PROTECTED] writes:
I just thought I'd report it here in case it wasn't supposed to
happen, but from what you say, it seems like it's a feature.
Well, it's more of a historical hangover. Personally I'd not
At 11:37 AM 3/13/2008, Scott Marlowe wrote:
I remember seeing something about some problems that using the
tablespace per table option on some mysql site... goes to look...
paraphrased from the Mysql Performance Blod... Using the
innodb_file_per_table=1 setting really tends to work against
At 09:47 PM 3/11/2008, rrahul wrote:
Hi,
I am a database professional but have never used Postgre. My client was
exploring the posiblity of using Postgre instead of Mysql and wnated to know
the comments from the community.
I waned you people you post your views on the following comparision
At 08:48 AM 2/9/2008, Alvaro Herrera wrote:
Joshua D. Drake escribió:
Richard Broersma Jr wrote:
I personally wouldn't even mind having a PG polo that has 3rd part
vendor logos on the sleeves if that would help make PG polo shirts
available.
O.k., o.k. :) I will look into costs.
Hmm, did
At 09:09 PM 11/30/2007, Trevor Talbot wrote:
The controller always exists, so it's not moving a point of failure;
if a controller goes you've lost the disk anyway.
Anecdotal - I have found smart raid controllers to fail more often
than dumb scsi controllers (or even SATA/PATA controllers),
Hi,
Found this post on Slashdot which I found interesting, any comments?
--- post follows ---
by Anonymous Coward on Wed Nov 28, '07 03:23 PM (#21509173)
Speak for your database -- postgresql does.
Postgresql's table inheritance is a flawed concept and has nothing to do
with the *type
At 03:17 AM 12/1/2007, Jeff Davis wrote:
The impedance mismatch has more to do with the fact that the meaning of
an application's internal data structures changes frequently (through
revisions of the code), while data in a database needs to be consistent
across long periods of time. So, a
Hi,
Anyone have comparisons/benchmarks to give some
idea of the potential performance gains?
Say compared to doing the stuff here:
http://www.postgresql.org/docs/8.2/static/populate.html
Regards,
Link.
At 09:35 AM 11/5/2007, Toru SHIMOGAKI wrote:
Dimitri, thank you for your quoting. I'm a
At 06:32 PM 9/6/2007, Richard Huxton wrote:
Two other tips for bulk-updates like this:
1. Do as many columns in one go as you can
2. Only update rows that need updating
When you've finished, a CLUSTER/VACUUM FULL can be useful too.
How about: make sure you have enough free space because the
At 11:48 PM 8/27/2007, Trevor Talbot wrote:
On 8/27/07, Jonah H. Harris [EMAIL PROTECTED] wrote:
On 8/27/07, Tom Lane [EMAIL PROTECTED] wrote:
that and the lack of evidence that they'd actually gain anything
I find it somewhat ironic that PostgreSQL strives to be fairly
non-corruptable,
At 03:15 PM 8/28/2007, Kamil Srot wrote:
Andrew, Alvaro... well, sure SQL injection is possibility I cannot
ignore... (and sure as dad of this
application, I think it's not the case :-) ... just kidding...
As even the injected SQL will be shown in the logs, so we'll know
more after some time.
At 11:28 PM 8/22/2007, Dmitry Koterov wrote:
Hello.
We are trying to use HP CISS contoller (Smart Array E200i) with
internal cache memory (100M for write caching, built-in power
battery) together with Postgres. Typically under a heavy load
Postgres runs checkpoint fsync very slow:
At 01:30 AM 8/24/2007, Murali Maddali wrote:
options like a different driver I can use or through stored procedures. I
have to compare each column in each row before doing the update.
Do you have to compare with all rows, or just one? Can your
comparison make use of an index?
Link.
At 09:26 PM 7/26/2007, James B. Byrne wrote:
Is there a way to use a key larger than 256 bits and is there any reason
why this would not be useful in practice? Our standard key sizes here
seem to by either 1024 or 2048.
Hi,
There's a difference between a symmetric key, and a public key. 256
At 05:13 AM 7/25/2007, James B. Byrne wrote:
I can connect from the httpd host to the postgresql host using psql and it
shows that an ssl connection with a 256 bit key is in use. However, I
would like to verify that the web app is also using ssl and I cannot seem
to find any logging setting or
Hi,
Sorry, this really isn't postgresql specific, but I figure there are
lots of smarter people around here.
Say I have lots of different objects (thousands or even millions?).
Example: cow, grass, tiger, goat, fish, penguin.
BUT I'm not so interested in defining things by linking them to
At 01:58 AM 6/22/2007, dfx wrote:
I tryied it but get errors on create user postgres.
Is there some workaround?
Upgrade to Windows XP SP2? Or Win2K?
Regards,
Link.
---(end of broadcast)---
TIP 9: In versions below 8.0, the planner will ignore
At 01:26 AM 6/9/2007, Billings, John wrote:
Does anyone think that PostgreSQL could benefit from using the video
card as a parallel computing device? I'm working on a project using
Nvidia's CUDA with an 8800 series video card to handle non-graphical
algorithms. I'm curious if anyone thinks
Hi,
I've been wondering, what O/S or hardware feature would be useful for
databases?
If Postgresql developers could get the CPU and O/S makers to do
things that would make certain things easier/faster (and in the long
term) what would they be?
By long term I mean it's not something that's
At 01:42 AM 6/1/2007, Alvaro Herrera wrote:
Vincenzo Romano escribió:
Hi all.
I'd like to know whether there is any real world evaluation (aka test) on
performances of the NUMERIC data type when compared to FLOAT8 and FLOAT4.
The documentation simply says that the former
is much slower than
At 03:25 AM 5/25/2007, A.M. wrote:
Indeed. Wouldn't it be a cool feature to persists transaction states
across connections so that a new connection could get access to a
sub- transaction state? That way, you could make your schema changes and
test them with any number of test clients (which
At 04:43 AM 5/12/2007, Dhaval Shah wrote:
1. Large amount of streamed rows. In the order of @50-100k rows per
second. I was thinking that the rows can be stored into a file and the
file then copied into a temp table using copy and then appending those
rows to the master table. And then dropping
At 01:11 PM 2/22/2007, John Smith wrote:
On 2/21/07, Lincoln Yeoh lyeoh@pop.jaring.my wrote:
MySQL: the PHP of databases.
'd appreciate if you stick to the subject.
jzs
OK sorry... That was more of a footnote.
Link.
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At 10:22 PM 2/22/2007, Tim Tassonis wrote:
Chris wrote:
An empty string is a KNOWN value. You know exactly what that value
is - it's an empty string.
A NULL is UNKNOWN - it doesn't have a value at all.
I do still think it is a bit of an oddity, the concept of the null
column. From my
At 12:54 AM 2/23/2007, Rodrigo Gonzalez wrote:
PHP is easy and cheap to start, so there are lots of programmers
using it, and someone like you, or any other company, can take a
cheap programmer to do the work. Most of programmer use it with
mysql, now this is the question to answerwhy?
At 01:30 AM 2/23/2007, Joshua D. Drake wrote:
Answer for this is a bit complex, more newbies howtos, more people
saying that is better and so on
Yeah. Would be good if we can figure out something that would help
postgresql increase its usage or mind share.
O.k. this is bizarre. One,
At 02:16 AM 2/23/2007, Joshua D. Drake wrote:
We do not compete with MySQL.
Does MySQL have the mindshare of the ignorant? Yes.
Does MySQL have the mindhare of the knowledgeable? No.
Our mindshare is *huge* with the knowledgeable.
I will take mindshare with the knowledgeable over the
At 07:31 PM 2/21/2007, Chad Wagner wrote:
On 2/20/07, gustavo halperin
mailto:[EMAIL PROTECTED][EMAIL PROTECTED] wrote:
I have a friend that ask me why postgresql is better than mysql.
I personally prefer posgresql, but she need to give in her work 3 or 4
strong reasons for that. I mean not to
At 12:02 AM 2/22/2007, Scott Marlowe wrote:
You can't change a table in any way without rewriting the whole thing,
resulting in a very long wait and a complete table lock on any alter
table action on big tables. Don't forget that if you've got a really
Oh yeah, that reminds me. rewriting the
At 09:36 AM 2/2/2007, Ron Johnson wrote:
OTOH, I still take a full base backup every night and keep ten days
worth of WAL files on our backup server, so I guess maybe I don't
*completely* trust it :-)
Or you don't trust tape to be 100% reliable.
Well so far tapes get chewed up by drives
At 08:12 AM 12/22/2006, Joshua D. Drake wrote:
With One Big Database, you can get a SAN and attach a whole lot of
disk space, but your mobo will only accept a certain number of DIMMs
and processors of certain designs. And when your growing mega
database maxes out your h/w, you're stuck.
Hi,
Seems ok. Works better than most corporate search engines - some tend
to show pages and pages of useless press releases when you are
searching for drivers, specifications etc.
But as long as the sites remain indexable to outside search engines,
people get to use whichever search engine
At 11:27 AM 9/14/2006 -0400, Arturo Perez wrote:
Hi all,
Any response to this:
http://www.internetnews.com/dev-news/article.php/3631831http://www.internetnews.com/dev-news/article.php/3631831
The title of the article is funny:
Is PHP The Cure For The 'Broken' Web?
In my opinion PHP is
At 01:12 AM 9/10/2006 +0330, Behrang Saeedzadeh wrote:
Hi,
Shouldn't this create statement trigger an error?
create table bar (col1 int not null default null);
No.
Shouldn't I be forbidden to insert null values into a non null column?
Yes.
Use not null default null when you want to
At 10:50 AM 7/10/2006 -0500, Scott Marlowe wrote:
On Sat, 2006-07-08 at 10:20, Joshua D. Drake wrote:
Unfortunately it would appear that I cannot vacuum full either as I
get an
out of memory error:
Also, this kind of points out that you might not have enough swap
space. On most
At 07:42 PM 6/11/2006 +0200, Florian Weimer wrote:
We recently had a partially failed disk in a RAID-1 configuration
which did not perform a write operation as requested. Consequently,
What RAID1 config/hardware/software was this?
Could be good to know...
Regards,
Link.
You are getting 190+ secs on the new hardware and 235 secs on the old?
Is the CPU usage maxed out? Assuming linux run top and then press 1.
If in both cases the CPU's are maxed out, then that explains why they are
about the same speed = both are 3GHz Intel CPUs, and your DB fits in RAM.
I've
At 10:38 AM 5/31/2006 +0200, Magnus Hagander wrote:
Since you're a Windows shop, you may already have the experience (and
even liceneses perhaps?) to run Microsoft Cluster Service (part of 2003
Enterprise Edition or 2000 Advanced Server). PostgreSQL will work fine
with it. Works with shared
At 11:53 AM 5/12/2006 -0400, Tom Lane wrote:
Scott Ribe [EMAIL PROTECTED] writes:
My damn powerbook drive recently failed with very little warning
It seems to me that S.M.A.R.T. reporting is a crock of shit. I've had ATA
drives report everything OK while clearly in the final throes of
Are the relevant COMMITs appearing in the log?
If the commits fail for whatever reason does/can the application (and
postgresql) log that?
If the commits are successful then you shouldn't have to need to look for
roll-backs.
It might be a good idea for teh webapp to log unsuccessful
At 10:01 AM 1/23/2006 -0600, Scott Marlowe wrote:
I'm not sure if it's Dell's BIOS on the mobos, or something with the LSI
cards, but the performance was substandard.
So if you're working somewhere that you simply have to use Dell (not
uncommon), at least make sure you get the LSI based RAID
At 11:49 AM 12/17/2005 +0800, Lincoln Yeoh wrote:
But in a column for license owner names, one might want tty and tyty
to be the same - one might have to have a multicolumn index depending on
the owner's locale of choice.
To make myself clear, one might want to store a person's name in one
At 01:40 PM 12/16/2005 -0500, Tom Lane wrote:
Nobody's said anything about giving up locale-sensitive sorting. The
question is about locale-sensitive equality: does it really make sense
that 'tty' = 'tyty'? Would your answer change in the context
'/dev/tty' = '/dev/tyty'? Are you willing to
Could it be faulty hardware?
Run memtest86? Test your drives?
At 10:49 AM 11/26/2005 +, Adam Witney wrote:
Any ideas what is going on here?
Thanks again for any help
Adam
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TIP 6: explain analyze is your friend
At 01:19 PM 11/21/2005 -0500, Dennis Veatch wrote:
I had thought just adding some fields called topsoil_start/topsoil_end,
gravel_start/gravel_end, etc. But them I'm left with how to take those values
and give to total depth for each layer and total depth of the well.
But I'm not sure that is
At 06:04 PM 11/16/2005 +0100, Martijn van Oosterhout wrote:
On Thu, Nov 17, 2005 at 12:29:25AM +0800, Lincoln Yeoh wrote:
My assumption is that pending transactions (e.g. locks and other metainfo)
will take much less memory than database backends.
They make take less memory but they take
At 11:27 PM 11/15/2005 -0500, Tom Lane wrote:
That said, it seems to me that the prepared-xacts infrastructure could
possibly support a separate suspend transaction and resume
transaction facility, if anyone wants to do the legwork to make it
happen. What this would actually be useful for is a
Hi,
Can we have a reconnect and reopen prepared/saved transactions feature?
Please? :)
I'm sure there'll be uses for it. e.g. the stuff I mentioned.
Maybe we can also use it to help migrate queries to a different node.
At 11:54 AM 11/12/2005 +0800, Lincoln Yeoh wrote:
At 02:22 PM 11/11
At 04:11 PM 11/10/2005 -0500, Tom Lane wrote:
Lincoln Yeoh lyeoh@pop.jaring.my writes:
Is it OK to use PREPARE TRANSACTION and COMMIT PREPARED in order to have
transactions that last longer than just a single web request?
Previously it was usually a bad idea to keep database connections
At 02:22 PM 11/11/2005 +0100, Martijn van Oosterhout wrote:
But once you've prepared a transaction, you can't reopen it, all you
can do is either commit it or abort it. I don't see how prepared
transaction relate to webapps at all.
See also the docs:
Hi,
Is it OK to use PREPARE TRANSACTION and COMMIT PREPARED in order to have
transactions that last longer than just a single web request?
Previously it was usually a bad idea to keep database connections alive
just to keep a transaction pending.
Now I'm thinking that we could keep
At 12:28 AM 11/2/2005 -0500, Jan Wieck wrote:
Using REPLACE INTO at one place and creating duplicates on purpose in
another seems to make zero sense to me. Until one can explain the reason
for that to me, I claim that a UNIQUE constraint on such key is a logical
consequence.
I believe it is
At 08:24 AM 10/30/2005 -0800, David Fetter wrote:
http://developer.postgresql.org/docs/postgres/plpgsql-control-structure
s.html#PLPGSQL-ERROR-TRAPPING
Erm, doesn't it have the same race conditions?
No, don't believe it does. Have you found some?
Depends on how you do things.
As I
At 06:29 AM 10/30/2005 -0800, David Fetter wrote:
On Fri, Oct 28, 2005 at 09:57:03PM -0400, blackwater dev wrote:
In MySQL, I can use the replace statement which either updates the
data there or inserts it. Is there a comporable syntax to use in
postgreSQL?
Not really, but here's an
At 05:33 PM 10/19/2005 -0700, Dann Corbit wrote:
If there is a significant performance benefit to not expanding text
columns in comparison operations, then it seems it should be OK.
I probably read the standard wrong, but it seems to me that varchar, char,
and bpchar columns should all
At 11:43 AM 10/15/2005 -0400, Tom Lane wrote:
Martijn van Oosterhout kleptog@svana.org writes:
Seems to me we'd be better off creating an option
lowercase_quoted_anyway which solves everything, at the expense of
being even less compliant.
I think that'll be a good option to have.
paying
will lock sometable nowait help?
http://developer.postgresql.org/docs/postgres/sql-lock.html
If it fails, something is in progress.
I believe there are also statement timeouts.
Regards,
Link.
At 11:56 AM 10/12/2005 +, Carlos Benkendorf wrote:
We have applications that are sometimes
If you don't trust the administrators you should find someone else to admin
your machine.
Main question: what do you need the administrators to do for you? If you
only need them to do a few things, then it is much easier to limit their
access.
Because, on most popular systems (e.g. C2-level
At 04:48 PM 10/5/2005 +0200, L van der Walt wrote:
The big problem is that the administrators works for the client and not
for me. I don't want the client to reverse engineer my database.
There might be other applications on the server so the administrators do
require root access.
If it's
Uh. Unless you've done something more than what you say, a windows
administrator can definitely access the data. Maybe most windows
administrators don't know how to do it, but it is possible.
I've viewed and changed data on a database on Windows without the database
administrator username and
At 12:24 PM 9/21/2005 +0100, Howard Cole wrote:
On a Win32 machine, can I backup a database if the backup file exceeds
2GB? In linux, I can split the backup file into multiple files. Can this
be done on Win32?
Max file size depends on file system used.
At 10:00 AM 9/20/2005 -0400, Vivek Khera wrote:
On Sep 14, 2005, at 9:45 AM, vinita bansal wrote:
I have a 4 proc. AMD Opteron machine with 32 GB RAM and ~400GB HDD
and a 40GB database. I need to take backup of this database and
restore it some other location (say some test environment). I
Apparently postgresql runs at 11% to 45% of normal speed in VMware
workstation. Basically it could be about 1/10th the performance for OLTP
stuff.
See here:
http://www.cl.cam.ac.uk/Research/SRG/netos/xen/performance.html
(Notice also that the web server performance is less than 30% of native).
At 09:45 PM 9/5/2005 +0100, Richard Huxton wrote:
Poul Møller Hansen wrote:
I'm trying to setup a database for 1 concurrent users for a test.
I have a system with 1GB of RAM where I will use 512MB for PostgreSQL.
It is running SuSE 9.3
I think you're being horribly optimistic if you
At 05:59 PM 8/9/2005 +0200, Martijn van Oosterhout wrote:
SQL_ASCII means that the database does no locale specific or language
specific encoding ever. It won't check what you send it either. If
you're content to let clients deal with any encoding issues, this may
be what you want.
But
I believe that one should leave such on-the-fly disk compression to the
O/S. Postgresql already does compression for TOAST.
However, maybe padding for alignment is a waste on the disk - disks being
so much slower than CPUs (not sure about that once the data is in memory ).
Maybe there should
They are quite different hardware.
How long does it take for the _first_ time you do the query on the Celeron
machine? The first time. Wait until everything has started up first and the
machine is quiescent.
How long does it take for the _second_ and _third_ times?
Do the same for all the
:33 AM 2/13/2005 -0800, J. Greenlees wrote:
Lincoln Yeoh wrote:
I think it should. But for phone numbers it may be better to reverse the
digits before indexing - usually whilst the area code changes, the last 4
or 5 digits don't change.
This way you can do a LIKE search on *5678. Where the number
At 09:57 AM 2/13/2005 +, Russ Brown wrote:
I've thought about things like this in the past, and a thought that
occurred to me was to add a functional index on just_digits(telephone) to
the table. Would this not allow the above query to use an index while
searching?
I think it should. But
While not an FAQ (yet?) I find it interesting that installing a QoS packet
scheduler would _improve_ response - (I'm assuming there's no other
concurrent traffic other than DB traffic).
Anyone know why this would be the case or have any ideas? Might it improve
performance for other network
At 12:14 PM 12/17/2004 -0500, Tom Lane wrote:
Bruno Wolff III [EMAIL PROTECTED] writes:
Greg Stark [EMAIL PROTECTED] wrote:
where postgres won't bother with the index since it will be slower
than just
resorting the entire table.
Using an index to do an order by is an order N operation. Doing
At 12:16 AM 12/13/2004 -0600, Guy Rouillier wrote:
(3) If we go with more disks, should we attempt to split tables and
indexes onto different drives (i.e., tablespaces), or just put all the
disks in hardware RAID5 and use a single tablespace?
Fast inserts = fast writes.
RAID5 = slower writes.
You
But isn't the problem when the planner screws up and not the sortmem setting?
There was my case where the 7.4 planner estimated 1500 distinct rows when
there were actually 1391110. On 7.3.4 it used about 4.4MB. Whereas 7.4
definitely used more than 400MB for the same query ) - I had to kill
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