Space required for universal table spaces
Notations used to calculate space for universal table spaces.
Notation | Description |
|---|---|
n | Number of rows in the table |
k | Average row length for the table |
p | PCTFREE |
f | FREEPAGE |
m | Page size in KB (4, 8, 16, or 32) |
j | Maximum rows per page (255 or MAXROWS) |
s | (100 - p) / 100 |
ps | Pages per space map (see Spacemap capacities) |
FLOOR | The operation of discarding the decimal portion of the real number |
CEILING | The operation of rounding a real number to the next highest integer |
MIN | Tthe operation of selecting the lowest integer value |
Total data pages and free pages for a table in a universal table space
The formulas in the following table are approximations.
Total data pages and free pages for a table
Value | Formula |
|---|---|
Usable space per page | FLOOR (s * ((m * 1024) - 22)) |
Rows per page | MIN (j, FLOOR (usable space per page / (k + 8))) |
Data pages | CEILING (n / rows per page) |
Free pages | FLOOR (data pages / MIN(f, (segsize - 1))), or 0 if f = 0 |
Total data and free pages for table | FLOOR ((data pages + free pages + segsize - 1) / segsize) * segsize |
Total number of pages in a universal table space
The formulas in the following table are approximations.
Total number of pages in a universal table space
Value | Formula |
|---|---|
Dictionary pages | |
Space map pages | CEILING ((total data and free pages + dictionary pages) / ps) |
Total tablepart pages | 1 + total data and free pages + dictionary pages + space map pages |
Total tablepart space (space in KB) | Total table space pages * 4 This value is rounded to the allocation unit. |
Total table space pages | Sum of the tablepart pages for each partition |
Total table space (space in KB) | Sum of the tablepart space of all partitions |