Sunday, June 28, 2009

Maximum Addressable Shared Memory in ASE 12.0.x and 12.5.x

The following table lists, by platform, the maximum size of shared memory for Adaptive Server Enterprise (ASE) 12.0.x and 12.5.x:
 
Platform32-bit ASE64-bit ASEComments
HP-UX 11.x (PA-RISC processor) 2.75 GB  16 EB  
HP-UX 11.x (Itanium2 processor) N/A 16 EB Available Q4 2003
HP Tru64 5.x N/A 16 EB  
IBM AIX 5.x 2.75 GB  16 EB  
SGI IRIX 6.x 4 GB 16 EB  
Sun Solaris 8 (sparc processor)  3.78 GB 16 EB  
Sun Solaris 8 (Intel x86 processor) 3.75 GB  N/A  
Windows 2000, 2003 and XP ~1.75 GB *  N/A See note below
Red Hat Enterprise Linux
(Intel x86 processor) 
2.7 GB N/A  
Red Hat Enterprise Linux
(Itanium2 processor)
N/A 16 EB Available Q4 2003
Mac OSX  2 GB  N/A  

Notes:

  • One Exabyte equals 2^60, or 1024 PetaByte. 16 EB is a theoretical limit; in practice, the actual value is limited by the total memory available on the system. ASE has been tested with a maximum of 256 GB of shared memory.

 


  •  * The maximum size of shared memory for 32-bit windows is approximately 1.75GB. This value can vary depending on the size of the ASE code and associated dlls, which also occupies the 2GB application space. You may need to reduce the max memory value in order to start ASE.

  • On some Windows 32-bit OS, you can use the /3GB option to boot the operating system; this allows ASE to use upto 3 GB shared memory. Check your specific OS version to see if it allows the /3GB option.

  • Each operating system has a default maximum shared-memory segment (for example, shm-max on HP Tru64). Check that the operating system is configured to allow the allocation of a shared-memory segment at least as large as ASE's total memory (12.0.x) or max memory (12.5.x) configuration parameter. See your platform's Installation Guide for Adaptive Server Enterprise for details.
  • ASE 12.5 changes how memory is allocated, resulting in changes to memory-related configuration parameters and introduction of new parameters. Be sure you understand the new memory configurations in ASE 12.5 when modifying server and/or operating system memory parameters. See What's New in Adaptive Server Enterprise? and the System Administration Guide for details.



The following table lists, by platform, the maximum size of shared memory for Adaptive Server Enterprise (ASE) 12.0.x and 12.5.x:
 
Platform32-bit ASE64-bit ASEComments
HP-UX 11.x (PA-RISC processor) 2.75 GB  16 EB  
HP-UX 11.x (Itanium2 processor) N/A 16 EB Available Q4 2003
HP Tru64 5.x N/A 16 EB  
IBM AIX 5.x 2.75 GB  16 EB  
SGI IRIX 6.x 4 GB 16 EB  
Sun Solaris 8 (sparc processor)  3.78 GB 16 EB  
Sun Solaris 8 (Intel x86 processor) 3.75 GB  N/A  
Windows 2000, 2003 and XP ~1.75 GB *  N/A See note below
Red Hat Enterprise Linux
(Intel x86 processor) 
2.7 GB N/A  
Red Hat Enterprise Linux
(Itanium2 processor)
N/A 16 EB Available Q4 2003
Mac OSX  2 GB  N/A  

Notes:

  • One Exabyte equals 2^60, or 1024 PetaByte. 16 EB is a theoretical limit; in practice, the actual value is limited by the total memory available on the system. ASE has been tested with a maximum of 256 GB of shared memory.

 


  •  * The maximum size of shared memory for 32-bit windows is approximately 1.75GB. This value can vary depending on the size of the ASE code and associated dlls, which also occupies the 2GB application space. You may need to reduce the max memory value in order to start ASE.

  • On some Windows 32-bit OS, you can use the /3GB option to boot the operating system; this allows ASE to use upto 3 GB shared memory. Check your specific OS version to see if it allows the /3GB option.

  • Each operating system has a default maximum shared-memory segment (for example, shm-max on HP Tru64). Check that the operating system is configured to allow the allocation of a shared-memory segment at least as large as ASE's total memory (12.0.x) or max memory (12.5.x) configuration parameter. See your platform's Installation Guide for Adaptive Server Enterprise for details.
  • ASE 12.5 changes how memory is allocated, resulting in changes to memory-related configuration parameters and introduction of new parameters. Be sure you understand the new memory configurations in ASE 12.5 when modifying server and/or operating system memory parameters. See What's New in Adaptive Server Enterprise? and the System Administration Guide for details.



Saturday, June 27, 2009

What is 'Compatibility Mode' in ASE 15.0.3 ESD#1?

At the end of March 2009, version 15.0.3 ESD#1 of Sybase Adaptive Server Enterprise (ASE) was released. This ESD
contained a new feature named 'compatibility mode'.

Compatibility mode is a query processing enhancement in ASE 15.0.3 ESD#1 that allows qualifying T‐SQL queries to
be processed with a method of query optimization and query execution very similar to that used in ASE 12.5,
instead of using the ASE 15 query processing algorithms.

Compatibility mode can be enabled server‐wide for the entire ASE server, as well as for an individual session only.
By default, compatibility mode is disabled. To enable it on server level, set the configuration parameter 'enable
compatibility mode' to 1 (when set to 0, it is disabled):

        
sp_configure 'enable compatibility mode', 1

To override the server‐wide compatibility mode setting for an individual session, use this syntax:

      
  set compatibility_mode on






At the end of March 2009, version 15.0.3 ESD#1 of Sybase Adaptive Server Enterprise (ASE) was released. This ESD
contained a new feature named 'compatibility mode'.

Compatibility mode is a query processing enhancement in ASE 15.0.3 ESD#1 that allows qualifying T‐SQL queries to
be processed with a method of query optimization and query execution very similar to that used in ASE 12.5,
instead of using the ASE 15 query processing algorithms.

Compatibility mode can be enabled server‐wide for the entire ASE server, as well as for an individual session only.
By default, compatibility mode is disabled. To enable it on server level, set the configuration parameter 'enable
compatibility mode' to 1 (when set to 0, it is disabled):

        
sp_configure 'enable compatibility mode', 1

To override the server‐wide compatibility mode setting for an individual session, use this syntax:

      
  set compatibility_mode on