Cost of routine
You can specify cost only for user-defined routines written in C.
The relative cost of the routine is used by the query optimizer
to determine the order in which to process WHERE clauses in a SELECT
statement. Expensive routines are called after inexpensive routines.
A cost of
0
indicates that the routine costs about
the same as the routines in the reference list that have a cost of 0
.
The reference list shows all user-defined routines created in the
project. The standard formula for computing routine cost is: lines_of_code + (I/O_operations x 100)
Because the optimizer compares routine costs, the actual cost is irrelevant; only the relative cost matters. However, follow the general formula to ensure that your routines interact with other DataBlade® module routines in a predictable way.