Use the Estimate Size window to estimate the amount of storage space
required for a new or existing table or index. The estimated storage
space is determined from the definition of a particular table and its
dependent indexes. Minimum and maximum storage values are estimated for
these objects.
There are several reasons to estimate the space requirements for tables and
indexes.
- You want to create a new table and you want to know how large to make the
table space.
- You want to create a new table based on the size estimate of an existing
table.
- You want to rearrange a table space. For example, you want to move
a table from table space A to table space B and want to know much space the
table uses in table space A.
- You want to know how much space different objects occupy in the table
space because the system is running out of storage space.
| Note: | For DB2 Extended Enterprise Edition Databases, size estimates are based on
the logical size of the data in the table instead of by database
partition.
|
Fields and controls
To estimate the size for a table:
- Open the Estimate Size window.
- Optional: If recent statistics are not available for the table or
index, click Run statistics before
updating the New total number of rows and
New average row length fields and running
a size estimate. The calculation of the size estimate can then be based
on more accurate information. The Run Statistics
window opens.
- Either accept the default or select a different value for New total number of rows.
- To view the size estimates for the new value, click Refresh.
- Either accept the default or select a different value for New average row length.
- To view the size estimates for the new value, click Refresh.
- Optional: Either accept the default or select a different value for
Display sizes in units of. The
size estimates change to use the selected value.
Related information