By Whei-Jen Chen
Read or Download Sap Solutions on IBM DB2 Udb V8.2.2 Handbook PDF
Best languages & tools books
Booklet by means of Lien, David A.
Ranging from the idea that figuring out the rules of concurrent programming is essential to constructing disbursed computing structures, this ebook first offers the elemental theories of concurrent computing after which introduces the programming languages that support enhance allotted computing platforms at a excessive point of abstraction.
Extra resources for Sap Solutions on IBM DB2 Udb V8.2.2 Handbook
The database manager shared memory is used for instance level tasks such as monitoring and auditing, etc. The usage of the database manager shared memory is defined by a set of database manager configuration parameters: INSTANCE_MEMORY parameter: Defines the lower bound of the amount of memory that should be reserved for instance management. By default, it is set to AUTOMATIC, that is, DB2 will calculate the amount of instance memory needed for the current configuration. DB2 will also allocate some additional memory for an overflow buffer.
The ACTIVATE DATABASE command or the first connection to the database would activate a database, while the deactivate database command or the last connection disconnect would deactivate a database. The database shared memory is used for many database level tasks such as shared sorts, backup/restore, load, logging, locking, and SQL executions. The minimum amount that will be allocated is now controlled by the DATABASE_MEMORY database configuration parameter. It is usually recommended to set its value to AUTOMATIC so that DB2 will calculate the amount of memory needed.
Let us now look at some examples: CREATE DATABASE RED ON D: PAGESIZE 16 K CREATE DATABASE RED ON D: PAGESIZE 16384 Both examples create a database called RED using page size 16 K. The three table spaces SYSCATSPACE, TEMPSPACE1, and USERSPACE1, and the default buffer pool, IBMDEFAULTBP, are created with 16 K page size. 2. The idea behind this concept is that DB2 UDB can manage its storage space by itself. This is a very important feature for SAP systems. It allows DB2 UDB to run with minimum or no interaction of the database administrator.