On 21-4-2007 1:42 Mark Kirkwood wrote:
I don't think that will work for the vector norm i.e:
|x - y| = sqrt(sum over j ((x[j] - y[j])^2))
I don't know if this is usefull here, but I was able to rewrite that
algorithm for a set of very sparse vectors (i.e. they had very little
overlapping fac
On Thu, 26 Apr 2007, Bill Moran wrote:
I've seen marketing material that claims that modern NTFS doesn't suffer
performance problems from fragmentation.
You're only reading half of the marketing material then. For a balanced
picture, read the stuff generated by the companies that sell defrag
Folks,
we in astronomy permanently work with billiards objects with spherical
atributes and have several sky-indexing schemes. See my page
for links http://www.sai.msu.su/~megera/wiki/SkyPixelization
We have q3c package for PostgreSQL available from q3c.sf.net, which
we use in production with t
On Fri, 27 Apr 2007, Alexander Staubo wrote:
On 4/20/07, Andrew Lazarus <[EMAIL PROTECTED]> wrote:
I have a table with 2.5 million real[] arrays. (They are points in a
time series.) Given a new array X, I'd like to find, say, the 25
closest to X in some sense--for simplification, let's just say
Hi,
I have pg 8.1.4 running in
Windows XP Pro
wirh a Pentium D
and I notice that I can not use more than 50% of the cpus (Pentium D has 2
cpus), how can I change the settings to use the 100% of it.
Regards,
Andrew Retzlaff
_
Adv
Carlos Moreno <[EMAIL PROTECTED]> writes:
> ... But, wouldn't it make sense that the configure script
> determines the amount of physical memory and perhaps even do a HD
> speed estimate to set up defaults that are closer to a
> performance-optimized
> configuration?
No. Most copies of Postgres
Steve Crawford wrote:
Have you changed _anything_ from the defaults? The defaults are set so
PG will run on as many installations as practical. They are not set for
performance - that is specific to your equipment, your data, and how you
need to handle the data.
Is this really the sensible thin
Is there a reason you are not using postgis. The R tree indexes are
designed for exactly this type of query and should be able to do it very
quickly.
Hope that helps,
Joe
> I have this table:
>
> CREATE TABLE test_zip_assoc (
> id serial NOT NULL,
> f_id integer DEFAULT 0 NOT NULL,
>
Sergey Tsukinovsky wrote:
Just for the record - the hardware that was used for the test has the
following parameters:
AMD Opteron 2GHZ
2GB RAM
LSI Logic SCSI
And you ran FreeBSD 4.4 on it right? This may be a source of high cpu
utilization in itself if the box is SMP or dual core, as multi-c
On 4/27/07, Alexander Staubo <[EMAIL PROTECTED]> wrote:
[snip]
PostGIS implements the whole GIS stack, and it's so good at this that
it's practically the de facto tool among GIS analysts. Installing
PostGIS into a database is simple, and once you have done this, you
can augment your table with a
On 24 Apr 2007 14:26:46 -0700, zardozrocks <[EMAIL PROTECTED]> wrote:
I have this table:
CREATE TABLE test_zip_assoc (
id serial NOT NULL,
f_id integer DEFAULT 0 NOT NULL,
lat_radians numeric(6,5) DEFAULT 0.0 NOT NULL,
long_radians numeric(6,5) DEFAULT 0.0 NOT NULL
);
CRE
On Tue, 2007-04-24 at 10:30, Sergey Tsukinovsky wrote:
> Thanks for this reply, Ron.
> This is almost what I was looking for.
>
> While the upgrade to the latest version is out of the question (which
> unfortunately for me became the subject of this discussion) still, I was
> looking for the ways
zardozrocks wrote:
I have this table:
CREATE TABLE test_zip_assoc (
id serial NOT NULL,
f_id integer DEFAULT 0 NOT NULL,
lat_radians numeric(6,5) DEFAULT 0.0 NOT NULL,
long_radians numeric(6,5) DEFAULT 0.0 NOT NULL
);
CREATE INDEX lat_radians ON test_zip_assoc USING btree
On Tue, 2007-04-24 at 16:26, zardozrocks wrote:
> I have this table:
>
> CREATE TABLE test_zip_assoc (
> id serial NOT NULL,
> f_id integer DEFAULT 0 NOT NULL,
> lat_radians numeric(6,5) DEFAULT 0.0 NOT NULL,
> long_radians numeric(6,5) DEFAULT 0.0 NOT NULL
> );
Like someo
On 4/20/07, Andrew Lazarus <[EMAIL PROTECTED]> wrote:
I have a table with 2.5 million real[] arrays. (They are points in a
time series.) Given a new array X, I'd like to find, say, the 25
closest to X in some sense--for simplification, let's just say in the
usual vector norm. Speed is critical he
NUMERIC operations are very slow in pgsql. Equality comparisons are somewhat
faster, but other operations are very slow compared to other vendor's NUMERIC.
We've sped it up a lot here internally, but you may want to consider using
FLOAT for what you are doing.
- Luke
Msg is shrt cuz m on ma t
zardozrocks wrote:
lat_radians numeric(6,5) DEFAULT 0.0 NOT NULL,
long_radians numeric(6,5) DEFAULT 0.0 NOT NULL
Native data types such as integer or real are much faster than numeric.
If you need 6 digits, it's better to multiply your coordinates by 10^6
and store as INTEGER
Shohab Abdullah wrote:
>
> Dear,
> We are facing performance tuning problem while using PostgreSQL Database
> over the network on a linux OS.
> Our Database consists of more than 500 tables with an average of 10K
> records per table with an average of 20 users accessing the database
> simultaneous
In response to zardozrocks <[EMAIL PROTECTED]>:
> I have this table:
>
> CREATE TABLE test_zip_assoc (
> id serial NOT NULL,
> f_id integer DEFAULT 0 NOT NULL,
> lat_radians numeric(6,5) DEFAULT 0.0 NOT NULL,
> long_radians numeric(6,5) DEFAULT 0.0 NOT NULL
> );
> CREATE I
On 24 Apr 2007 14:26:46 -0700, zardozrocks <[EMAIL PROTECTED]> wrote:
I have this table:
CREATE TABLE test_zip_assoc (
id serial NOT NULL,
f_id integer DEFAULT 0 NOT NULL,
lat_radians numeric(6,5) DEFAULT 0.0 NOT NULL,
long_radians numeric(6,5) DEFAULT 0.0 NOT NULL
);
CRE
I have this table:
CREATE TABLE test_zip_assoc (
id serial NOT NULL,
f_id integer DEFAULT 0 NOT NULL,
lat_radians numeric(6,5) DEFAULT 0.0 NOT NULL,
long_radians numeric(6,5) DEFAULT 0.0 NOT NULL
);
CREATE INDEX lat_radians ON test_zip_assoc USING btree (lat_radians);
CREAT
Thanks for this reply, Ron.
This is almost what I was looking for.
While the upgrade to the latest version is out of the question (which
unfortunately for me became the subject of this discussion) still, I was
looking for the ways to improve the performance of the 7.0.2 version.
Extensive use of
On Apr 20, 12:07 pm, [EMAIL PROTECTED] (Andrew Lazarus) wrote:
> I have a table with 2.5 million real[] arrays. (They are points in a
> time series.) Given a new array X, I'd like to find, say, the 25
> closest to X in some sense--for simplification, let's just say in the
> usualvectornorm. Speed i
On Sat, 2007-04-21 at 15:17, Jeroen Kleijer wrote:
> Hi all,
>
> I'm a bit new to PostgreSQL and database design in general so forgive me
> for asking stupid questions. ;-)
>
> I've setup a PostgreSQL database on a Linux machine (2 processor, 1GB
> mem) and while the database itself resides on a
Gregory Stark <[EMAIL PROTECTED]> writes:
> In the case of a performance-critical file like the WAL that's always read
> sequentially it may be to our advantage to defeat this technique and force it
> to be allocated sequentially. I'm not sure whether any filesystems provide any
> option to do so.
Hello!
I would do the following (in that order):
1.) Check for a performant application logic and application design (e.g.
degree of granularity of the Java Hibernate Mapping, are there some
object iterators with hundreds of objects, etc.)
2.) Check the hibernate generated queries and whether t
"Craig A. James" <[EMAIL PROTECTED]> writes:
> More specifically, this problem was solved on UNIX file systems way back in
> the
> 1970's and 1980's. No UNIX file system (including Linux) since then has had
> significant fragmentation problems, unless the file system gets close to 100%
> full. If
Bill Moran wrote:
In response to Heikki Linnakangas <[EMAIL PROTECTED]>:
Can anyone else confirm this? I don't know if this is a windows-only
issue, but I don't know of a way to check fragmentation in unix.
I can confirm that it's only a Windows problem. No UNIX filesystem
that I'm aware of s
> In response to Jim Nasby <[EMAIL PROTECTED]>:
>> I was recently running defrag on my windows/parallels VM and noticed
>> a bunch of WAL files that defrag couldn't take care of, presumably
>> because the database was running. What's disturbing to me is that
>> these files all had ~2000 fragm
In response to Heikki Linnakangas <[EMAIL PROTECTED]>:
[snip]
> >> Can anyone else confirm this? I don't know if this is a windows-only
> >> issue, but I don't know of a way to check fragmentation in unix.
> >
> > I can confirm that it's only a Windows problem. No UNIX filesystem
> > that I'm
Bill Moran wrote:
In response to Jim Nasby <[EMAIL PROTECTED]>:
I was recently running defrag on my windows/parallels VM and noticed
a bunch of WAL files that defrag couldn't take care of, presumably
because the database was running. What's disturbing to me is that
these files all had ~200
In response to Jim Nasby <[EMAIL PROTECTED]>:
> I was recently running defrag on my windows/parallels VM and noticed
> a bunch of WAL files that defrag couldn't take care of, presumably
> because the database was running. What's disturbing to me is that
> these files all had ~2000 fragments.
Please try to post to one list at a time.
I've replied to this on the -performance list.
--
Richard Huxton
Archonet Ltd
---(end of broadcast)---
TIP 6: explain analyze is your friend
Please try to keep postings to one mailing list - I've replied to the
performance list here.
Shohab Abdullah wrote:
Dear,
We are facing performance tuning problem while using PostgreSQL Database
over the network on a linux OS.
Our Database consists of more than 500 tables with an average of 10
Dear,
We are facing performance tuning problem while using PostgreSQL Database
over the network on a linux OS.
Our Database consists of more than 500 tables with an average of 10K
records per table with an average of 20 users accessing the database
simultaneously over the network. Each table has
Jim Nasby wrote:
On Apr 25, 2007, at 8:51 AM, Paweł Gruszczyński wrote:
where u6 stores Fedora Core 6 operating system, and u0 stores 3
partitions with ext2, ext3 and jfs filesystem.
Keep in mind that drives have a faster data transfer rate at the
outer-edge than they do at the inner edge [.
"Jim Nasby" <[EMAIL PROTECTED]> writes:
> AIUI, char, varchar and text all store their data in *exactly* the same way in
> the database; char only pads data on output, and in the actual tables it
> still
> contains the regular varlena header. The only reason I've ever used char in
> other datab
The outer track / inner track performance ratio is more like 40 percent.
Recent example is 78MB/s outer and 44MB/s inner for the new Seagate 750MB drive
(see http://www.storagereview.com for benchmark results)
- Luke
Msg is shrt cuz m on ma treo
-Original Message-
From: Jim Nasby [
On Apr 25, 2007, at 8:51 AM, Paweł Gruszczyński wrote:
where u6 stores Fedora Core 6 operating system, and u0 stores 3
partitions with ext2, ext3 and jfs filesystem.
Keep in mind that drives have a faster data transfer rate at the
outer-edge than they do at the inner edge, so if you've got a
On Apr 23, 2007, at 7:16 AM, Merlin Moncure wrote:
On 4/20/07, chrisj <[EMAIL PROTECTED]> wrote:
I have a table that contains a column for keywords that I expect
to become
quite large and will be used for web searches. I will either
index the
column or come up with a simple hashing algorit
I was recently running defrag on my windows/parallels VM and noticed
a bunch of WAL files that defrag couldn't take care of, presumably
because the database was running. What's disturbing to me is that
these files all had ~2000 fragments. Now, this was an EnterpriseDB
database which means t
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