Re: [GENERAL] Create extension tablefunc fails with "wrong ELF class: ELFCLASS32"

2012-10-20 Thread John R Pierce
On 10/20/12 10:21 AM, Jan Mechtel wrote: Our webhoster moved us to a 64Bit CentOS. I installed postgresql-9.1.3 from source. instead, you probably should have installed postgres from the yum.postgresql.com repository. something like this... # rpm -Uvh http://yum.postgresql.org/9.1/redhat

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2012-10-20 Thread Jan Mechtel

Re: [GENERAL] obtain the difference between successive rows

2012-10-20 Thread Berend Tober
Thalis Kalfigkopoulos wrote: On Sat, Oct 20, 2012 at 8:02 AM, Raymond O'Donnell wrote: On 20/10/2012 11:54, ochaussavoine wrote: I have a table 'tmvt' with a field 'created' in the row, and would like to compute the difference between successive rows. The solution I found is: I think you can

Re: [GENERAL] Create extension tablefunc fails with "wrong ELF class: ELFCLASS32"

2012-10-20 Thread Jan Mechtel
Thanks for the quick reply, This could indeed be a solution since the webhosting migrated the old folder I used for installation on 32bit. I am not very familar with linux, I'd like to ask for two clarifications: >If so, you should start from a fresh source tree; or run "make clean" or >"make m

[GENERAL] Create extension tablefunc fails with "wrong ELF class: ELFCLASS32"

2012-10-20 Thread Jan Mechtel
Our webhoster moved us to a 64Bit CentOS. I installed postgresql-9.1.3 from source. I run into trouble when trying to create the tablefunc extension b2blogin_mailrocket=# create extension tablefunc; ERROR: could not load library "/home/b2blogin/lib/postgresql/tablefunc.so": /home/b2blogin/lib/po

Re: [GENERAL] obtain the difference between successive rows

2012-10-20 Thread Berend Tober
Виктор Егоров wrote: 2012/10/20 Berend Tober : Your suggestion almost worked as is for this, except that you have to note that reading for meter #2 and meter #3 overlap ... You can do … OVER(PARTITION BY electric_meter_pk ORDER BY reading_date) to split you data by meter. That looks like

Re: [GENERAL] Create extension tablefunc fails with "wrong ELF class: ELFCLASS32"

2012-10-20 Thread Jeff Janes
On Sat, Oct 20, 2012 at 11:00 AM, Jan Mechtel wrote: > Thanks for the quick reply, > > This could indeed be a solution since the webhosting migrated the old folder > I used for installation on 32bit. Sorry, I don't really know what this means. They just copied the folder, or the migration was mo

Re: [GENERAL] Create extension tablefunc fails with "wrong ELF class: ELFCLASS32"

2012-10-20 Thread Jan Mechtel
Thanks a lot, this worked. I read to detail the tablefunc.so and then go to the postgres-9.1.3/contrib/ and call make + make install there. On 20 October 2012 20:02, Jan Mechtel wrote: > Thanks for the quick reply, > This could indeed be a solution since the webhosting migrated the old > folder

Re: [GENERAL] Create extension tablefunc fails with "wrong ELF class: ELFCLASS32"

2012-10-20 Thread Jan Mechtel
Thanks for the quick reply, This could indeed be a solution since the webhosting migrated the old folder I used for installation on 32bit. I am not very familar with linux, I'd like to ask for two clarifications: >If so, you should start from a fresh source tree; or run "make clean" or >"make mai

Re: [GENERAL] Create extension tablefunc fails with "wrong ELF class: ELFCLASS32"

2012-10-20 Thread Jeff Janes
On Sat, Oct 20, 2012 at 10:33 AM, Jan Mechtel wrote: > Our webhoster moved us to a 64Bit CentOS. I installed postgresql-9.1.3 from > source. Did you also install contrib from the same source? > > I run into trouble when trying to create the tablefunc extension > > b2blogin_mailrocket=# create ex

Re: [GENERAL] obtain the difference between successive rows

2012-10-20 Thread Виктор Егоров
2012/10/20 Berend Tober : > Your suggestion almost worked as is for this, except that you have to note > that reading for meter #2 and meter #3 overlap (I briefly owned two houses), > and that seemed to confuse the lag() function: > > SELECT > electric_meter_pk, > lag(reading_date) > OVER(

[GENERAL] Create extension tablefunc fails with "wrong ELF class: ELFCLASS32"

2012-10-20 Thread Jan Mechtel
Our webhoster moved us to a 64Bit CentOS. I installed postgresql-9.1.3 from source. I run into trouble when trying to create the tablefunc extension b2blogin_mailrocket=# create extension tablefunc; ERROR: could not load library "/home/b2blogin/lib/postgresql/tablefunc.so": /home/b2blogin/lib/po

Re: [GENERAL] obtain the difference between successive rows

2012-10-20 Thread Raymond O'Donnell
On 20/10/2012 17:50, Tom Lane wrote: > "Raymond O'Donnell" writes: >> On 20/10/2012 17:23, Tom Lane wrote: >>> FWIW, Postgres is reasonably smart about the case of multiple window >>> functions with identical window definitions --- once you've got one >>> lag() in the query, adding more isn't goin

Re: [GENERAL] obtain the difference between successive rows

2012-10-20 Thread Berend Tober
Berend Tober wrote: Raymond O'Donnell wrote: On 20/10/2012 17:02, Berend Tober wrote: Thalis Kalfigkopoulos wrote: How would you get the previous reading (and perhaps the previous read date) to also appear ... Just include them in the SELECT: Well, that is surprisingly easy! How about this

Re: [GENERAL] obtain the difference between successive rows

2012-10-20 Thread Tom Lane
"Raymond O'Donnell" writes: > On 20/10/2012 17:23, Tom Lane wrote: >> FWIW, Postgres is reasonably smart about the case of multiple window >> functions with identical window definitions --- once you've got one >> lag() in the query, adding more isn't going to cost much. > Out of curiosity, would

Re: [GENERAL] obtain the difference between successive rows

2012-10-20 Thread Chris Angelico
On Sun, Oct 21, 2012 at 3:29 AM, Raymond O'Donnell wrote: > On 20/10/2012 17:23, Tom Lane wrote: >> Having said that, they are pretty expensive. I tend to agree that doing >> the processing on the application side might be faster --- but only if >> you've got a place to put such code there. If y

Re: [GENERAL] obtain the difference between successive rows

2012-10-20 Thread Berend Tober
Raymond O'Donnell wrote: On 20/10/2012 17:02, Berend Tober wrote: Thalis Kalfigkopoulos wrote: How would you get the previous reading (and perhaps the previous read date) to also appear ... Just include them in the SELECT: Well, that is surprisingly easy! How about this then: the table in

Re: [GENERAL] obtain the difference between successive rows

2012-10-20 Thread Raymond O'Donnell
On 20/10/2012 17:23, Tom Lane wrote: > Chris Angelico writes: >> To be quite honest, I would simply read the table directly and then do >> the processing in an application language :) But two window functions >> should do the trick. Whether or not it's actually more efficient that >> way is anothe

Re: [GENERAL] obtain the difference between successive rows

2012-10-20 Thread Tom Lane
Chris Angelico writes: > To be quite honest, I would simply read the table directly and then do > the processing in an application language :) But two window functions > should do the trick. Whether or not it's actually more efficient that > way is another question. FWIW, Postgres is reasonably s

Re: [GENERAL] obtain the difference between successive rows

2012-10-20 Thread Raymond O'Donnell
On 20/10/2012 17:02, Berend Tober wrote: > Thalis Kalfigkopoulos wrote: >> SELECT current_meter_reading - lag(current_meter_reading) OVER(ORDER >> BY current_reading_date) AS kWh_diff, extract('days' FROM >> current_reading_date - lag(current_reading_date) OVER(ORDER BY >> current_reading_date)) as

Re: [GENERAL] obtain the difference between successive rows

2012-10-20 Thread Berend Tober
Thalis Kalfigkopoulos wrote: SELECT current_meter_reading - lag(current_meter_reading) OVER(ORDER BY current_reading_date) AS kWh_diff, extract('days' FROM current_reading_date - lag(current_reading_date) OVER(ORDER BY current_reading_date)) as num_service_days FROM mytable; How would you get t

Re: [GENERAL] obtain the difference between successive rows

2012-10-20 Thread Thalis Kalfigkopoulos
> What about if there is more than one column you want the difference for (... > coincidentally I am writing a article on this topic right now! ...), say a > table which is used to record a metered quantity at not-quite regular > intervals: > > CREATE TABLE electricity > ( > current_reading_date

Re: [GENERAL] obtain the difference between successive rows

2012-10-20 Thread Chris Angelico
On Sun, Oct 21, 2012 at 2:30 AM, Berend Tober wrote: > What about if there is more than one column you want the difference for (... > coincidentally I am writing a article on this topic right now! ...), say a > table which is used to record a metered quantity at not-quite regular > intervals: > ..

Re: [GENERAL] obtain the difference between successive rows

2012-10-20 Thread Berend Tober
Thalis Kalfigkopoulos wrote: On Sat, Oct 20, 2012 at 8:02 AM, Raymond O'Donnell wrote: On 20/10/2012 11:54, ochaussavoine wrote: I have a table 'tmvt' with a field 'created' in the row, and would like to compute the difference between successive rows. The solution I found is: I think you can

Re: [GENERAL] obtain the difference between successive rows

2012-10-20 Thread Thalis Kalfigkopoulos
On Sat, Oct 20, 2012 at 8:02 AM, Raymond O'Donnell wrote: > On 20/10/2012 11:54, ochaussavoine wrote: >> Hi, >> I have a table 'tmvt' with a field 'created' in the row, and would like to >> compute the difference between successive rows. The solution I found is: >> > > I think you can do it with a

Re: [GENERAL] obtain the difference between successive rows

2012-10-20 Thread Raymond O'Donnell
On 20/10/2012 11:54, ochaussavoine wrote: > Hi, > I have a table 'tmvt' with a field 'created' in the row, and would like to > compute the difference between successive rows. The solution I found is: > > It is complicate and very long to perform. The problem could be simply > solved with MySql by

[GENERAL] obtain the difference between successive rows

2012-10-20 Thread ochaussavoine
Hi, I have a table 'tmvt' with a field 'created' in the row, and would like to compute the difference between successive rows. The solution I found is: It is complicate and very long to perform. The problem could be simply solved with MySql by creating a new field and updating it using a statement