Resource Governor makes use of Knowledge bases to control
which requests are run and which are not. A Knowledge base is built
from Business rules, Data Rules or both.
- Business rules are user coded using a wizard and/or editor
and use information from the current environment. They do not use
- Data rules are generated by combining historic usage data (monitored
data) and user defined Thresholds.
There are two types of Knowledge bases, Global and Data Source.
- A Global Knowledge base can only contain Business rules
and there can only be one active at any given time. Its execution
is dependent on the nature of the rules that it contains. If the
rules are at the command level, for example disallow SELECT *, then
execution is tied to which data request types are monitored. While
a rule disallowing access to any data source that starts with the
characters “ca” will always be executed.
- A Data Source Knowledge base is applied to individual data sources
(Synonyms or Direct passthru requests) and therefore is only executed
if the data source is referenced in a request. If multiple data
sources are referenced in the request (JOIN or FROMs in an SQL statement),
only one Knowledge base will be processed and will be selected based
on the first data source in the request list that is being actively