table are substantially outdated the qf driven process monitors query results on a table this process modifies the runstats profile and or recommends execution of runstats whenever it detects either that the configuration parameters have been set improperly or that the statistics are outdated the scheduler component combines the output of these two processes and triggers the execution of runstats on appropriate sets of tables and at appropriate times in general the scheduler causes runstats to be executed on one or more tables during a u201c maintenance iteration u201d which occurs within a specified time period called a u201c maintenance window u201d the frequency and length of maintenance windows can be controlled by the dba the left side of fig1 depicts functionality that is implemented in the db2 engine i e the query processor with optimizer and plan execution the data manipulation language dml processor and the monitors that facilitate several of db2 39 s autonomic capabilities the right side of fig1 depicts several analyzers and a scheduler that have been added to the db2 health monitor to realize automated statistics collection the analyzers periodically investigate the output of the monitors and recommend to the scheduler a set of tables on which to collect statistics the upper portion.