Each table and each index on a table has an object allocation map (OAM). The OAM is stored on pages allocated to the table or index. A single OAM page holds allocation mapping for between 2,000 and 63,750 data pages or index pages. In most cases, the number of OAM pages required is close to the minimum value. To calculate the number of OAM pages for the table, use:
Formula 
Example 


Number of reserved data pages / 63,750 
= 
Minimum OAM pages 
750,000 / 63,750 
= 
12 
Number of reserved data pages / 2000 
= 
Maximum OAM pages 
750,000 / 2000 
= 
375 
Add the number of OAM pages to the earlier totals to determine the total number of pages required:
Formula 
Example 


Minimum 
Maximum 
Minimum 
Maximum 

Data pages 
+ 
+ 
750000 
750000 
OAM pages 
+ 
+ 
12 
375 
Total 
750012 
750375 