Re: PostgreSQL with PostGIS on embedded hardware

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Re: PostgreSQL with PostGIS on embedded hardware

От:
"Joshua D. Drake" <jd@commandprompt.com>
Дата:
On Fri, 2009-05-08 at 18:06 +0200, Paolo Rizzi wrote:
> Hi all,
> recently I came across a question from a customer of mine, asking me if 
> it would feasible to run PostgreSQL along with PostGIS on embedded hardware.
> They didn't give me complete information, but it should be some kind of 
> industrial PC with a 600MHz CPU. Memory should be not huge nor small, 
> maybe a couple of GBytes, hard disk should be some type of industrial 
> Compact Flash of maybe 16 GBytes.
> 

Well the CPU is slow the but rest isn't so bad.

> They are thinking about using this setup on-board of public buses and 
> trams, along with a GPS receiver, for self-localization. So that when 
> the bus or tram enters defined zones or passes near defined points, 
> events are triggered.
> The database could probably be used completely read-only or almost that.
> 
> What performances do you think would be possible for PostgreSQL+PostGIS 
> on such hardware???
> 

If you aren't doing a lot of writing I don't see a huge barrier to this.

Sincerely,

Joshua D. Drkae


-- 
PostgreSQL - XMPP: jdrake@jabber.postgresql.org
   Consulting, Development, Support, Training
   503-667-4564 - http://www.commandprompt.com/
   The PostgreSQL Company, serving since 1997

Re: PostgreSQL with PostGIS on embedded hardware

От:
Tom Lane <tgl@sss.pgh.pa.us>
Дата:
Paolo Rizzi  writes:
> Are you saying that PostgreSQL+PostGIS can actually run on a 
> smartphone??? Intriguing...
> Did anyone ever actually tried that???

If it's a supported CPU type and you've got a suitable build toolchain,
sure.  Seven or eight years ago we were getting a good laugh out of the
fact that you could run PG on a PlayStation 2.

The real issue with the kind of hardware you're describing is going to
be the finite write lifetime of a flash device.  For a low-update
application it'll probably be okay, but PG could very easily destroy a
flash in no time if you aren't careful to minimize updates.

			regards, tom lane

Re: PostgreSQL with PostGIS on embedded hardware

От:
Greg Stark <stark@enterprisedb.com>
Дата:
On Mon, May 11, 2009 at 5:05 PM, Stefan Kaltenbrunner
 wrote:
>> Good to know!!! I imagine that on a PS3 it would be _really_ fast... :-)
>
> well not really - while it is fairly easy to get postgresql running on a PS3
> it is not a fast platform. While the main CPU there is a pretty fast Power
> based core it only has 256MB of Ram and a single SATA disk available(though
> you could add some USB disks).

The nice thing about it is that TPC-C and other benchmarks all specify
their bottom-line number in some unit like Transaction per second PER
DOLLAR. So using a PS3 should be able to get ridiculously good results
compared to expensive server hardware...

-- 
greg

PostgreSQL with PostGIS on embedded hardware

От:
Paolo Rizzi <gis@oicom.com>
Дата:
Hi all,
recently I came across a question from a customer of mine, asking me if 
it would feasible to run PostgreSQL along with PostGIS on embedded hardware.
They didn't give me complete information, but it should be some kind of 
industrial PC with a 600MHz CPU. Memory should be not huge nor small, 
maybe a couple of GBytes, hard disk should be some type of industrial 
Compact Flash of maybe 16 GBytes.

They are thinking about using this setup on-board of public buses and 
trams, along with a GPS receiver, for self-localization. So that when 
the bus or tram enters defined zones or passes near defined points, 
events are triggered.
The database could probably be used completely read-only or almost that.

What performances do you think would be possible for PostgreSQL+PostGIS 
on such hardware???

Bye
Paolo

Re: PostgreSQL with PostGIS on embedded hardware

От:
Paolo Rizzi <gis@oicom.com>
Дата:
Joshua D. Drake ha scritto:
> On Fri, 2009-05-08 at 18:06 +0200, Paolo Rizzi wrote:
>> Hi all,
>> recently I came across a question from a customer of mine, asking me if 
>> it would feasible to run PostgreSQL along with PostGIS on embedded hardware.
>> They didn't give me complete information, but it should be some kind of 
>> industrial PC with a 600MHz CPU. Memory should be not huge nor small, 
>> maybe a couple of GBytes, hard disk should be some type of industrial 
>> Compact Flash of maybe 16 GBytes.
>>
> 
> Well the CPU is slow the but rest isn't so bad.
> 
>> They are thinking about using this setup on-board of public buses and 
>> trams, along with a GPS receiver, for self-localization. So that when 
>> the bus or tram enters defined zones or passes near defined points, 
>> events are triggered.
>> The database could probably be used completely read-only or almost that.
>>
>> What performances do you think would be possible for PostgreSQL+PostGIS 
>> on such hardware???
>>
> 
> If you aren't doing a lot of writing I don't see a huge barrier to this.
> 
> Sincerely,
> 
> Joshua D. Drkae
Thank you!!!
Indeed I also think it could be done, but I searched the Web and found 
no previous experience of the like, so maybe it's just too weird putting 
a spatial-enabled RDBMS on-board buses...!?!

Anyway I found the TurnKey PostgreSQL appliance. It's a small 
Ubuntu-based live-cd with PostgreSQL and PostGIS preconfigured.
I could suggest these people to try it out on hardware similar to what 
they intend to use, to have a feel of how it behaves.

Bye
Paolo



Re: PostgreSQL with PostGIS on embedded hardware

От:
Paolo Rizzi <gis@oicom.com>
Дата:
>  
> 
>> -----Mensaje original-----
>> De: Paolo Rizzi
>>
>> Hi all,
>> recently I came across a question from a customer of mine, 
>> asking me if it would feasible to run PostgreSQL along with 
>> PostGIS on embedded hardware.
>> They didn't give me complete information, but it should be 
>> some kind of industrial PC with a 600MHz CPU. Memory should 
>> be not huge nor small, maybe a couple of GBytes, hard disk 
>> should be some type of industrial Compact Flash of maybe 16 GBytes.
>>
>> They are thinking about using this setup on-board of public 
>> buses and trams, along with a GPS receiver, for 
>> self-localization. So that when the bus or tram enters 
>> defined zones or passes near defined points, events are triggered.
>> The database could probably be used completely read-only or 
>> almost that.
>>
> 
> Hi Paolo,
> 
> I'm not really responding to your question. It happens that I collaborated
> on a postgres/postgis based solution for public transportation and the
> motive why you are trying to put the database in the embedded hardware is
> puzzling to me. In this solution we used a centralized PG database, the
> devices in buses captured geographical position and other business related
> data and fetched it by cellular network to the central server. 
> Calculations on position where made on the server and related events where
> fetched back accordingly.
> 
> If possible, I would like to know what drives you to put a database on each
> device? You dont have a wireless link on each unit?
Indeed I was as puzzled as you when they described me their idea, but I 
think it makes sense. The buses and trams have to be independent of the 
radio link  because there are certain operations that have to performed 
at the right moment in the right place (like oiling wheels or letting 
down sand or salt or some other action).
However they _are_ going to use a centralized server, and putting the 
same technology (PostgreSQL/PostGIS) both on-board and on-center, would 
let them simplify development, configuration and maintenance.
Now that hardware is continuously getting cheaper and more powerful, 
moving "intelligence" on-board may be a smart move...

> 
> 
>> What performances do you think would be possible for 
>> PostgreSQL+PostGIS on such hardware???
> 
> We never considered that solution so I couldn´t say.
In fact I searched the Web and found nobody that did that before :-)

> 
>> Bye
>> Paolo
>>
> 
> Regards,
> Fernando.

Bye
Paolo



Re: PostgreSQL with PostGIS on embedded hardware

От:
Paolo Rizzi <gis@oicom.com>
Дата:
> 
>> They didn't give me complete information, but it should be some kind 
>> of industrial PC with a 600MHz CPU. Memory should be not huge nor 
>> small, maybe a couple of GBytes, hard disk should be some type of 
>> industrial Compact Flash of maybe 16 GBytes.
> 
>     It should work perfectly OK.
> 
>     Remember that you need a fast CPU if you have a database server that 
> processes many queries from many users simultaneously.
>     Since your "server" will process very few queries (maybe one per 
> second, something like that) even a slow (by modern standards) 600 MHz 
> CPU will be more than enough...
>     I'd say for such an application, your hardware is way overkill (it 
> would work on a smartphone...) but since hardware is so cheap...
A smartphone... you're right, I didn't think of that, but the hardware I 
described is very much like the one of a modern smartphone!!!
Are you saying that PostgreSQL+PostGIS can actually run on a 
smartphone??? Intriguing...
Did anyone ever actually tried that???

Bye
Paolo

Re: PostgreSQL with PostGIS on embedded hardware

От:
Paolo Rizzi <gis@oicom.com>
Дата:
>> Are you saying that PostgreSQL+PostGIS can actually run on a 
>> smartphone??? Intriguing...
>> Did anyone ever actually tried that???
> 
> If it's a supported CPU type and you've got a suitable build toolchain,
> sure.  Seven or eight years ago we were getting a good laugh out of the
> fact that you could run PG on a PlayStation 2.
Good to know!!! I imagine that on a PS3 it would be _really_ fast... :-)

> 
> The real issue with the kind of hardware you're describing is going to
> be the finite write lifetime of a flash device.  For a low-update
> application it'll probably be okay, but PG could very easily destroy a
> flash in no time if you aren't careful to minimize updates.
This is something I thought about too, but it's something that those 
people (this client of mine) should be well aware of, anyway I'll point 
it out for them.

Anyway it seems interesting the fact that newer Flashes use several 
techniques, such as wear leveling, to spread writes across the least 
used cells. But this leads to files physical fragmentation, and it may 
be a case where sequential scans are actually slower than random ones!!!

> 
> 			regards, tom lane

Bye
Paolo

Re: PostgreSQL with PostGIS on embedded hardware

От:
Stefan Kaltenbrunner <stefan@kaltenbrunner.cc>
Дата:
Paolo Rizzi wrote:
>>> Are you saying that PostgreSQL+PostGIS can actually run on a 
>>> smartphone??? Intriguing...
>>> Did anyone ever actually tried that???
>>
>> If it's a supported CPU type and you've got a suitable build toolchain,
>> sure.  Seven or eight years ago we were getting a good laugh out of the
>> fact that you could run PG on a PlayStation 2.
> Good to know!!! I imagine that on a PS3 it would be _really_ fast... :-)

well not really - while it is fairly easy to get postgresql running on a 
PS3 it is not a fast platform. While the main CPU there is a pretty fast 
Power based core it only has 256MB of Ram and a single SATA disk 
available(though you could add some USB disks).


Stefan

Re: PostgreSQL with PostGIS on embedded hardware

От:
Stefan Kaltenbrunner <stefan@kaltenbrunner.cc>
Дата:
Greg Stark wrote:
> On Mon, May 11, 2009 at 5:05 PM, Stefan Kaltenbrunner
>  wrote:
>>> Good to know!!! I imagine that on a PS3 it would be _really_ fast... :-)
>> well not really - while it is fairly easy to get postgresql running on a PS3
>> it is not a fast platform. While the main CPU there is a pretty fast Power
>> based core it only has 256MB of Ram and a single SATA disk available(though
>> you could add some USB disks).
> 
> The nice thing about it is that TPC-C and other benchmarks all specify
> their bottom-line number in some unit like Transaction per second PER
> DOLLAR. So using a PS3 should be able to get ridiculously good results
> compared to expensive server hardware...

I kinda doubt that - the PS3 is certainly not server grade hardware so 
you can only compare it to a desktop and I would bet that the typical 
desktop you get for the 400€(you can get >4GB RAM a quadcore CPU for 
that) price of a PS3 is going to outperform it significantly for almost 
every workload...


Stefan

Re: PostgreSQL with PostGIS on embedded hardware

От:
"Fernando Hevia" <fhevia@ip-tel.com.ar>
Дата:
 

> -----Mensaje original-----
> De: Paolo Rizzi
> 
> Hi all,
> recently I came across a question from a customer of mine, 
> asking me if it would feasible to run PostgreSQL along with 
> PostGIS on embedded hardware.
> They didn't give me complete information, but it should be 
> some kind of industrial PC with a 600MHz CPU. Memory should 
> be not huge nor small, maybe a couple of GBytes, hard disk 
> should be some type of industrial Compact Flash of maybe 16 GBytes.
> 
> They are thinking about using this setup on-board of public 
> buses and trams, along with a GPS receiver, for 
> self-localization. So that when the bus or tram enters 
> defined zones or passes near defined points, events are triggered.
> The database could probably be used completely read-only or 
> almost that.
> 

Hi Paolo,

I'm not really responding to your question. It happens that I collaborated
on a postgres/postgis based solution for public transportation and the
motive why you are trying to put the database in the embedded hardware is
puzzling to me. In this solution we used a centralized PG database, the
devices in buses captured geographical position and other business related
data and fetched it by cellular network to the central server. 
Calculations on position where made on the server and related events where
fetched back accordingly.

If possible, I would like to know what drives you to put a database on each
device? You dont have a wireless link on each unit?


> What performances do you think would be possible for 
> PostgreSQL+PostGIS on such hardware???

We never considered that solution so I couldn´t say.

> 
> Bye
> Paolo
> 

Regards,
Fernando.

Re: PostgreSQL with PostGIS on embedded hardware

От:
PFC <lists@peufeu.com>
Дата:

> They didn't give me complete information, but it should be some kind of  
> industrial PC with a 600MHz CPU. Memory should be not huge nor small,  
> maybe a couple of GBytes, hard disk should be some type of industrial  
> Compact Flash of maybe 16 GBytes.

	It should work perfectly OK.

	Remember that you need a fast CPU if you have a database server that  
processes many queries from many users simultaneously.
	Since your "server" will process very few queries (maybe one per second,  
something like that) even a slow (by modern standards) 600 MHz CPU will be  
more than enough...
	I'd say for such an application, your hardware is way overkill (it would  
work on a smartphone...) but since hardware is so cheap...

Re: PostgreSQL with PostGIS on embedded hardware

От:
PFC <lists@peufeu.com>
Дата:

> A smartphone... you're right, I didn't think of that, but the hardware I  
> described is very much like the one of a modern smartphone!!!
> Are you saying that PostgreSQL+PostGIS can actually run on a  
> smartphone??? Intriguing...
> Did anyone ever actually tried that???

	While the performance of ARM cpus used in smartphones, PDAs, etc, is  
pretty good, this hardware is optimized for small size and low power use,  
thus you generally get quite low memory bandwidth, the problem of Flash  
endurance, and lack of standard interfaces to hook up to the rest of your  
system.
	Embedded PC-Compatible hardware in the 600 MHz range you mention would  
probably get a DIMM memory module (maybe for the only reason that  
mass-production makes them so cheap) so you'd get a much higher memory  
bandwidth, and much larger RAM. Even if the CPU is only 2x faster than a  
smartphone, if the memory bandwidth is 10x higher, you'll see the  
difference. It would also have standard interfaces, very useful for you,  
and you can hook it up to a real SSD (not a micro-SD card) with real flash  
wear leveling algorithms.

	But yeah since today's smartphones are more powerful that the desktops of  
10 years ago (which ran PG just fine) it would probably work, if you can  
run Linux on it...
FAQ