The calculator panel allows you to specify parameters required to estimate a table size and recommend values for first and next extent sizes.
To calculate estimated table size and extent sizes, press Calculate button at the bottom of the panel. When there are multiple tables in the panel, the calculation is always performed for all tables in the list.
You can specify following parameters:
Estimated Number of Rows - enter a number of rows that will be loaded to this table initially after your application is deployed. By default, for existing tables, this number is set to current number of rows in the table, but it is not necessarily the actual number of rows that will be loaded when the table is deployed in the production system. For example, in your development or QA system, a table can be loaded with 10000 rows for testing, but when deployed in the production, it will be loaded with 2 millions of rows.
Expected Monthly Growth% - this number is used to set the size for the next extent. The calculator sets table's next extent size so that it could hold data for 6 month of growth.
Index Fill % - index fill percentage defined for this index when the index was created. By default, IDS uses 90% fill factor but it can be overridden using CREATE INDEX statement or ONCONFIG file.
Estimated Data Size for TEXT and BYTE columns - if your table contains TEXT and BYTE columns that are stored in the same tablespace as the table (not stored in separate BlobSpace), you should provide average data size for each column data. For example, if you have BYTE column that holds small GIF files for icons, its average size could be 500 bytes. If you have TEXT column that holds descriptions of items in a catalog, the average size of each description can be 5Kb.
Estimated Fill % for VARCHAR / LVARCHAR columns - (it also applies to all variant size datatypes, such as NVARCHAR) You should enter average fill percentage to get a realistic estimate of table data size. If you want to be on the conservative size, you can use 100% fill factor that represents maximum size for these datatypes. For example, if you have VARCHAR(100) column and you enter 50% fill factor, the calculator will use 51 characters for estimating this column storage requirements. If you enter 100% fill factor, the calculator will use 101 characters for the same purpose.
The calculation results for a selected table are displayed in the bottom panel. If you have multiple tables in the calculator, the summary calculation results are also displayed in the table grid.
After the calculation is performed, you can use Table Reorganizer wizard to apply recommended calculated extent sizes to a table. Press Reorganize button to open the wizard for a selected table.