Re: pg 10.1 missing libpq in postgresql-devel

2018-01-27 Thread support-tiger 

sorry for delay but ran some tests on older version pg gem - still fails

it fails on building the config file with simply missing libpq-fe.h,  
cannot find libpq-fe.h


I suspect it is a problem with using the pgdg repository and that 
postgresql get "10" added to them ie postgresql10-devel and maybe the 
gem code does not recognize that.   Since vers 10 is not breaking it 
does not make sense (i guess fedora)  to rename vers 10 with the "10" - 
maybe they just love the python 2 / 3 fiasco and want to extend it to 
postgresql.





On 01/25/2018 03:59 PM, Adrian Klaver wrote:

On 01/25/2018 12:20 PM, support-tiger wrote:
running postgresql 10.1 on Fedora 27. Cannot install ruby pg gem due 
to missing libpq-fe.h file.  This is usually found in 
postgresql-devel but 


What was the error message returned when you tried to install originally?

it is not in fedora 27 postgresql10-devel. If install 
postgresql-devel (9.6) the gem installs without problem but afraid 
this will interfere with 10.1  How can we install the necessary 
libpq-fe.h  ?  thks








--
Support Dept
Tiger Nassau, Inc.
www.tigernassau.com
406-624-9310

Re: pg 10.1 missing libpq in postgresql-devel

2018-01-27 Thread Adrian Klaver 

On 01/27/2018 04:34 PM, support-tiger wrote:

sorry for delay but ran some tests on older version pg gem - still fails


With what error message?

What Ruby gem?



it fails on building the config file with simply missing libpq-fe.h, 
cannot find libpq-fe.h


Well it is there:

rpm -qlp postgresql10-devel-10.1-1PGDG.f27.x86_64.rpm | grep libpq-fe.h
warning: postgresql10-devel-10.1-1PGDG.f27.x86_64.rpm: Header V4 
DSA/SHA1 Signature, key ID 442df0f8: NOKEY

/usr/pgsql-10/include/libpq-fe.h



I suspect it is a problem with using the pgdg repository and that 
postgresql get "10" added to them ie postgresql10-devel and maybe the 
gem code does not recognize that.   Since vers 10 is not breaking it 
does not make sense (i guess fedora)  to rename vers 10 with the "10" - 
maybe they just love the python 2 / 3 fiasco and want to extend it to 
postgresql.


Previous versions used version numbering also:

https://yum.postgresql.org/9.6/fedora/fedora-26-x86_64/

postgresql96-devel-9.6.6-1PGDG.f26.x86_64.rpm

My guess it that the config script for the gem is not taking into 
account that Postgres changed from a three part versioning system X.Y.z 
to a two part system X.y(where lower case is minor version) from 9.6.0 
to 10.1.







On 01/25/2018 03:59 PM, Adrian Klaver wrote:

On 01/25/2018 12:20 PM, support-tiger wrote:
running postgresql 10.1 on Fedora 27. Cannot install ruby pg gem due 
to missing libpq-fe.h file.  This is usually found in 
postgresql-devel but 


What was the error message returned when you tried to install originally?

it is not in fedora 27 postgresql10-devel. If install 
postgresql-devel (9.6) the gem installs without problem but afraid 
this will interfere with 10.1  How can we install the necessary 
libpq-fe.h  ?  thks











--
Adrian Klaver
adrian.kla...@aklaver.com

Best way to select a random row from a derived table

2018-01-27 Thread Ryan Murphy 
Hello hackers and postgressers,

I am aware of 2 ways to select a random row from a table:

1) select * from table_name order by random() limit 1;
-- terribly inefficient

2) select * from table_name tablesample system_rows(1) limit 1;
-- only works on tables, not views or subqueries

Is there an option that is reasonably efficient and can be used on views
and subqueries?

Thanks!
Ryan