How is the page size of rootdbs determined?
I have an IDS instance running 11.50.FC4 on AIX. The OS pagesize is as follows:
$ pagesize4096
The rootdbs page size is also 4096 bytes as shown below:
Dbspaces
address number flags fchunk nchunks pgsize flags owner name
700000071953028 1 0x40001 1 1 4096 N B informix root
On a server running Ubuntu 8.04.4 LTS I initialized an IDS instance also using 11.50.FC4.
The Ubuntu pagesize is also 4096 bytes:
$ getconf PAGESIZE4096
However, the rootdbs has a page size of 2048 bytes:
Dbspaces
address number flags fchunk nchunks pgsize flags owner name
4e04d028 1 0x40001 1 1 2048 N B informix rootdbs
Can anyone tell me:-
1. How the default page size of the rootdbs is determined?
2. Whether it is possible to specify the page size for the rootdbs?
Many thanks.
On Monday, September 3, 2012 9:52:42 PM UTC-5, Desmodromic wrote:
> I have an IDS instance running 11.50.FC4 on AIX. The OS pagesize is as follows:
>
>
>
> $ pagesize>
> 4096
>
>
>
> The rootdbs page size is also 4096 bytes as shown below:
>
>
>
> Dbspaces
>
> address number flags fchunk nchunks pgsize flags owner name
>
> 700000071953028 1 0x40001 1 1 4096 N B informix root
>
>
>
> On a server running Ubuntu 8.04.4 LTS I initialized an IDS instance also using 11.50.FC4.
>
>
>
> The Ubuntu pagesize is also 4096 bytes:
>
>
>
> $ getconf PAGESIZE>
> 4096
>
>
>
> However, the rootdbs has a page size of 2048 bytes:
>
>
>
> Dbspaces
>
> address number flags fchunk nchunks pgsize flags owner name
>
> 4e04d028 1 0x40001 1 1 2048 N B informix rootdbs
>
>
>
> Can anyone tell me:-
>
>
>
> 1. How the default page size of the rootdbs is determined?
>
> 2. Whether it is possible to specify the page size for the rootdbs?
>
>
>
> Many thanks.
1) The instance's default page size is determined at source code compile time and I believe it is 2Kb for all unix platform but AIX which uses 4Kb.
2) You can not change the page size of the root dbspace. Also from a quick look in the documentation, logical logs and the physical log need to be in default page sized dbspaces.
Jacques Renaut
IBM Informix Advanced Support
APD Team