This read-only boolean indicates whether the performance counters reported for this particular PM interval row are trustworthy. An admin checks this before acting on the interval's coding violation, errored-second, or unavailable-second values, since data collected during a reboot, counter reset, or partial interval can be marked invalid and should be excluded from trend analysis. If this flag reads false for interval 1, the most recent, the last 15 minutes of stats shouldn't be used to judge whether a new alarm condition is real.