Use the following equation to determine the amount of usable data space for Record and Indicator modes:
The following parameter definitions are used with this equation:
Parameter | Definition |
---|---|
a | Number of rows being selected. |
RO | Row overhead (12 bytes per row). |
RP | Row parcel indicators; 8 bytes per row (rec start, rec end). |
RDS | Raw data size of each field returned to the user. |
b | Number of numeric columns in the ORDER BY clause (sort key). |
SNF | Sorted numeric fields (8 bytes each). |
SCF | Formatted size of each character column in the ORDER BY clause. If an order operation is done on a column defined as VARCHAR(200), 200 characters are allowed, even if the value contains only 3 nonblank characters. The value for CF can be less than the CREATE TABLE definition of the string only if there is a FORMAT phrase. The formatted length of the character string must be rounded up to the next even value, then 2 more bytes must be added to the number. |
n | Number of columns being selected. |
IF | Record mode selects use indicator variables to represent nulls. IF is the constant 8, meaning that for each 8 columns selected, 1 byte is needed to represent a null column. |