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The QMF GovernorBecause QMF uses dynamic SQL, the RLF can be used to govern QMF resource use. To control the usage of QMF, a row would be inserted specifying the following:
If necessary, multiple rows could be inserted with varying resource limits for different authids. However, the QMF Governor can govern QMF use independently from DB2 and SQL use. The QMF Governor provides the capability to prompt users or to cancel threads based on excessive resource use. Resource use is either a CPU time limit or a limit based on the number of rows retrieved by a single query. The operation of the QMF Governor is controlled by rows inserted into a QMF control table named Q.RESOURCE_TABLE . DDL to create this table is shown in the following SQL statement: CREATE TABLE Q.RESOURCE_TABLE (RESOURCE_GROUP CHAR(16) NOT NULL , RESOURCE_OPTION CHAR(16) NOT NULL , INTVAL INTEGER, FLOATVAL FLOAT, CHARVAL VARCHAR(80) ) IN DSQDBCTL.DSQTSGOV ; Values inserted into the first three columns of this table control QMF resource governing . The IBM-supplied QMF Governor does not use the last two columns , FLOATVAL and CHARVAL . The following list shows the values that can be supplied for the RESOURCE_OPTION column, indicating the types of QMF governing available:
When the QMF Governor is set to prompt when reaching a particular threshold, the users are told the amount of CPU time consumed and the number of rows retrieved. This prompt looks like the following: DSQUE00 QMF governor prompt: Command has run for nnnnnn seconds of CPU times and fetched mmmmmm rows of data. ==> To continue QMF command press the "ENTER" key. ==> To cancel QMF command type "CANCEL" then press the "ENTER" key. ==> To turn off prompting type "NOPROMPT" then press the "ENTER" key. Users have the choice to continue or cancel their request. Users can request also that additional prompting be disabled. If the request is continued and prompting is not disabled, subsequent prompts are displayed as the limits are reached. Additionally, the QMF Governor might cancel a request if additional limits are met.
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