Not all metrics are maintained in the roll table for each system type. For example, MEM_EFFECTIVE is of the metrics that is not maintained in the roll table for its supported system types.
In order to produce an equivalent rolling average over the past 30 days, you would need to directly use the public view PV_SYS_DATA_D to compute the results you need.
I created an example query below that shows how to compute values from the two different approaches so that you can compare the two methods:
1. Obtain MEM_USED for Generic system over past 30 days using roll tables, and
2. Obtain MEM_REAL_USED for Generic system over past 30 days using the public view.
Michael D. West
ROUND(ENT_CONF_MODULE.GET_NUM_VALUE('SYS', ps.SYSID, 'TOTAL_REAL_MEM'), 0) AS MEM_SIZE,
ROUND(SERIES_MODULE.GET_ROLL_VALUE (30, 'AVG', 30, 'SYS', ps.SYSID, 'MEM_USED'), 0) AS MEM_USED,
FROM PV_SYS_METRIC pm
JOIN PV_SYS_DATA_D pd USING (SYSMETRICID)
WHERE TRUNC(pd.ts) >= TRUNC(sysdate - 30)
AND pm.METRIC = 'MEM_REAL_USED'
AND pm.SYSID = ps.SYSID
GROUP BY pm.SYSID
),0) AS MEM_REAL_USED
FROM PV_SYSTEM ps
WHERE ps.SYSTYPEID = 0;