tailieunhanh - Rampant TechPress Oracle Data Warehouse Management PHẦN 8

không phải là phân phối ngẫu nhiên trên đĩa sau đó các giá trị mẫu có thể phần nào tương quan. Chỉ thích hợp khi thực hiện một số liệu thống kê ước tính. method_opt - lựa chọn phương pháp định dạng sau nhưng sẽ được sử dụng trong tương lai. Thủ tục không có đối số. | ROBO Books Monograph Data Warehousing and Oracle8i Managing CPU Utilization for Data Warehouses in Oracle8i In data warehouses diverse groups of users may look at the data warehouse to find information important to their group. While we like to believe everyone is equal face it if the CEO wants a report his needs come over and above Joe Clerk s needs for a different report. In earlier releases of Oracle you could use profiles to restrict specific types of resources but this was unwieldy and produced unpredictable results. New in Oracle8i is the concept of Oracle resource groups. A resource group specification allows you to specify that a specific group of database users can only use a certain percentage of the CPU resources on the system. A resource plan must be developed that defines the various levels within the application and their percentage of CPU resources in a waterfall type structure where each subsequent levels percentages are based on the previous levels. Creating a Resource Plan Rather than have a simple CREATE RESOURCE PLAN command Oracle8i has a series of packages which must be run in a specific order to create a proper resource plan. All resource plans are created in a pending area before being validated and committed to the database. The requirements for a valid resource plan are outlined in the definition of the procedure below. Resource plans can have up to 32 levels with 32 groups per level allowing the most complex resource plan to be easily grouped. Multiple plans sub-plans and groups can all be tied together into an application spanning CPU resource utilization rule set. This rule set is known as a set of directives. An example would be a simple 2-tier plan like that shown in Figure 1. Page 84 COPYRIGHT 2003 Rampant TechPress. All Rights Reserved. ROBO Books Monograph Data Warehousing and Oracle8i Sub Plan Users CPU 60 Sub Group Online_Users CPU 70 Set level CPU_P1 in directive Sub Plan OTHER_GROUPS