Re: [PERFORM] High CPU usage / load average after upgrading to Ubuntu 12.04

2013-02-12 Thread Dan Kogan
Hi Will, Yes, I think we've seen some discussions on that. Our servers our hosted on Amazon Ec2 and upgrading the kernel does not seem so straight forward. We did a benchmark using pgbench on 3.5 vs 3.2 and saw an improvement. Unfortunately our production server would not boot off 3.5 so we ha

Re: [PERFORM] High CPU usage / load average after upgrading to Ubuntu 12.04

2013-02-12 Thread Dan Kogan
Thanks for the reply. We are still using postgresql-9.0-801.jdbc4.jar. It seemed to us that this is more related to the OS than the JDBC, version as we had the issue before we upgraded to 9.2. It might still be worth a try. Just out of curiosity, has anyone else experienced performance issues

[PERFORM] High CPU usage / load average after upgrading to Ubuntu 12.04

2013-02-12 Thread Dan Kogan
Hello, We upgraded from Ubuntu 11.04 to Ubuntu 12.04 and almost immediately obeserved increased CPU usage and significantly higher load average on our database server. At the time we were on Postgres 9.0.5. We decided to upgrade to Postgres 9.2 to see if that resolves the issue, but unfortunat

Re: [PERFORM] numerical primary key vs alphanumerical primary key

2013-02-12 Thread Claudio Freire
On Tue, Feb 12, 2013 at 12:05 PM, Grant Johnson wrote: > My experience has been that the performance advantage for numeric keys is > primarily an Oracle thing. However, Oracle is popular enough for people to > assume that it applies to databases in general. The advantage in PG also exists, only t

Re: [PERFORM] numerical primary key vs alphanumerical primary key

2013-02-12 Thread Florent Guillaume
For SQL Server, having a clustered index on a numeric incrementing key is much better than having a semi-random uuid primary key used as the clustered index itself. Florent On Tue, Feb 12, 2013 at 4:05 PM, Grant Johnson wrote: > My experience has been that the performance advantage for numeric k

Re: [PERFORM] numerical primary key vs alphanumerical primary key

2013-02-12 Thread Grant Johnson
My experience has been that the performance advantage for numeric keys is primarily an Oracle thing. However, Oracle is popular enough for people to assume that it applies to databases in general. Julien Cigar wrote: >The biggest difference in performance between text and integer keys is >us

Re: [PERFORM] numerical primary key vs alphanumerical primary key

2013-02-12 Thread Julien Cigar
The biggest difference in performance between text and integer keys is usually down to whether you're inserting in order or not. Inserting in order is tons faster regardless of the type, since it keeps the index unfragmented and doesn't cause page splits. On 02/04/2013 22:52, Anne Rosset wrote