Collection and Reorganization Schema

Definition

Collection and reorganization schemata are part of the Central Performance History (CPH) of the monitoring architecture. A schema of this type specifies how long data assigned to this schema (see Assigning Collection and Reorganization Schemata to Performance Values) is to be stored in the CPH with which granularity. There can also be a time zone into which the data is to be converted, and calculation rules for the aggregation (see Day Schema and Calendar Schema).

The data in the CPH is in different aggregates and temporal granularities. For an explanation of the relevant concepts, see aggregation. The following aggregates and granularities are used in the CPH:

	Possible Values
Aggregate	Day Week X days (X is any natural number) Month Quarter Year
Granularity	Minutes Quarter hour Hour Day

You can specify the storage period for the aggregates depending on their granularity - a granularity of minutes are normally not stored as long as values with a granularity of days. The main reason for this is the enormous storage requirements that long-term storage in a finer granularity would demand. Also, values with a very fine granularity (such as minutes) are not suitable for analyses over a long period of time, as the number of measurements for each measuring point rises with a coarser granularity and therefore ensures better statistics.

Use

There are two different screens that you can use to create and change the collection and reorganization schemata:

Structure

From one aggregate with a certain granularity, you can calculate all other equal or coarser aggregates with equal or coarser granularity.

Weekly and x day aggregates are an exception to this. These can be calculated from the day aggregates with a finer or equal granularity; however, you cannot calculate any other aggregates from them. The reason for this is that week and x day aggregates are outside the aggregate hierarchy, as weeks, for example, cannot be uniquely assigned to months, quarters, or years (a week can, for example, belong to two months). In contrast, a day always belongs uniquely to a month, a month always belongs uniquely to a quarter, and so on.

Tip

In this case, a month aggregate with a quarter-hourly granularity is to be stored for six months. From this aggregate, you can directly calculate all aggregates with all granularities that are in the solid rectangle highlighted in blue.

On the other hand, you cannot calculate any other aggregates from the aggregates in the dashed rectangle highlighted in red. You can only calculate values for the same aggregate with a coarser granularity from these (see arrows).