The space required by an outline can have two components.
The main area of the outline is a component of both disk and memory space requirements and is calculated using the following factors:
The number of members in the outline
The length, in characters, of member names and aliases
The attribute association area of an outline is a component only of disk space and is calculated using the following factors:
The number of members in each base dimension
The number of members in each attribute dimension
To estimate the size of the outline file:
Estimate the main area of the outline by multiplying the number of members by a name-length factor between 350 and 450 bytes.
If the database includes few aliases or very short aliases and short member names, use a smaller number within this range. If you know that the member names or aliases are very long, use a larger number within this range.
Because the name-length factor is an estimated average, the following formula provides only a rough estimate of the main area of the outline:
number of members * name-length factor = size of main area of outline
Note: | See Limits, for the maximum sizes for member names and aliases. |
For memory space requirements calculated later in this chapter, use the size of the main area of the outline.
For disk space requirements, if the outline includes attribute dimensions, calculate the size of the attribute association area for the database. Calculate the size of this area for each base dimension. Multiply the number of members of the base dimension by the sum of the count of members of all attribute dimensions associated with the base dimension, and then divide by 8:
(number of base-dimension members * sum of count of attribute-dimension members)/8 = size of attribute association area for a base dimension
Note: | Within the count of members, do not include Label Only members and shared members. |
Sum the attribute association areas of each dimension to determine the total attribute association area for the outline.
For the total disk space required for the outline, add together the main outline area and the attribute association area:
main area of outline + total attribute association area
Write the result of this calculation to the cell labeled DH in Table 247, Worksheet: Estimate of Disk Requirements for a Database.
Assume the outline has the following characteristics:
26,000 members
A name-length factor of 400 bytes
A base dimension Product (23,000 members—excluding Label Only members and shared members) with two attribute dimensions associated with it—Ounces (20 members) and Pkg Type (50 members)
A base dimension Market (2,500 members—excluding Label Only members and shared members) with one associated attribute dimension, Population (12 members)
Perform the following calculations:
Calculate the main area of the outline:
name-length factor of 400 bytes * 26,000 members = 10,400,000 bytes
Calculate the attribute association areas:
For the base dimension Product:
(23,000 * (20 + 50)) bits / 8 bits per byte = 201,250 bytes
For the base dimension Market:
(2,500 * 12) bits / 8 bits per byte = 3,750 bytes
Sum these areas for the total attribute association area for the database:
201,250 bytes + 3,750 bytes = 205,000 bytes
For a total estimate of outline disk space, add the main area of the outline and the total attribute association area:
10,400,000 bytes + 205,000 bytes = 10,605,000 bytes (outline disk space requirement)
Note: | Do not use this procedure to calculate outline memory space requirements. Use the process described in Outline Size Used in MemoryOutline. |