The maximum size of database buffer pools has been increased in Version 7.2 to exploit the capabilities of increased memory and address space. Larger buffer pools mean DB2 can put more data in memory, making data access and sorting faster.
Support for the increase in the maximum size of database buffer pools is enabled through:
DB2 Version 7.2 on Windows 2000 can now allocate buffer pools that use up to 64 GB of memory through the Microsoft Windows Address Windowing Extensions (AWE) API, which is supported on all versions of Windows 2000. With AWE support, the total size of DB2 buffer pools can reach up to 64 GB.
While all versions of Windows 2000 support this functionality, only the Windows 2000 Advanced Server and Datacenter Server provide the increased memory support.
To support AWE buffer pools, Windows 2000 must be configured correctly. This includes having the DB2_AWE registry variable set, associating the "lock pages in memory" privilege with the user under which DB2 is installed, and allocating the physical pages and the address window pages. See the DB2 Release Notes for more information.
DB2 Version 7.2 offers 64-bit support on AIX, HP-UX, and the Solaris Operating Environment to exploit the increased memory address space, and provides application libraries that can access DB2 databases from 64-bit applications.
Applications running on 64-bit operating systems benefit from the increased memory address space that these systems provide. For DB2 Universal Database, the 64-bit address space allows for the creation of larger buffer pools, sort heap, package caches, and other resources that require large amounts of memory. Additional memory improves the performance of many operations, especially sort and I/O operations.
For additional information, see the manual entitled Using DB2 Universal Database on 64-bit Platforms. This manual is available in PDF format on the Publications CD-ROM with the DB2 Manuals.
With DB2 Version 7.2, the maximum value allocated to the locklist configuration parameter has increased. This has a positive impact on database performance and the query optimizer. See the DB2 Release Notes for more information.