Cumulative Cost

The costs shown in the Operator Details window represent the estimated cumulative costs up to and including the point where the action represented by the operator is performed. These costs are estimated by the optimizer.

(If the operator type is RETURN, its cost is the estimated overall cost for the entire query.)

Note:

The cost is irrelevant if it is calculated using default statistics. For partitioned databases, all costs are for the node that uses the most resources.

The following costs are shown:

Total cost

The estimated cumulative cost of executing the current access plan (in timerons).

CPU cost

The estimated cumulative CPU cost (in number of instructions).

I/O cost

The estimated cumulative input/output (I/O) cost (in number of seeks and page transfers).

First row cost

The estimated cumulative effort (in timerons) required to produce the first row in the set of rows that results when the action represented by the operator is performed.

(This item is available in Full details mode only.)

Communication cost

The estimated cumulative communication cost (in number of IP (Internet Protocol) Frames).

First communication cost

The estimated cumulative communication cost (in number of IP Frames) required to produce the first row in the set of rows that results when the action represented by the operator is performed.

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