Easiest Way to Size an Oracle Database
SoftArt Solutions is an experienced Oracle consulting company that serves clients across the United States. Contact us with any questions you have on how to size an Oracle database or perform patching on your Oracle Database.
To size an Oracle database you can estimate a current database of similar size as the one you will need in your new application. You can also use capacity planning to find out how much space you will need for a new Oracle database.
Database size is the physical space that files consume on the disk. For current databases, you can use the following command to retrieve the size. However, that doesn’t mean that all of this space is allocated as there can be sections of the files that are not used.
select sum(bytes)/1024/1024 size_in_mb from dba_data_files;
How Do You Size an Oracle Database?
For this exercise, you will need a capacity planning spreadsheet.
Oracle database sizing estimates can be based on the sizes of the objects stored in various segments of related tablespaces.
To do this, you must first calculate the indexes and table sizes. In the Oracle DBA manual, there’s a section on sizing procedures so that a DBA can calculate a new database size manually four indexes and tables. However, we suggest that you download this spreadsheet which greatly simplifies the process.
How to Use the Spreadsheet?
This spreadsheet requires an input of table column sizes for date, character and number data types. You also need to input specifics about table items like percent free in a block, initial transactions and the number of rows. Also, the block size must be specified. If a table is clustered, that also impacts the size estimate.
The index DB spreadsheet only requires size inputs for the following items:
- Initial transactions
- Number of rows expected
- Percent free
- Blocksize
For non-unique indexes, answer the estimated percentage of time they will contain data.
What’s the Advantage of Using a Standardize Worksheet?
When you use the same spreadsheet to calculate Oracle database sizes, you can ensure that it’s a repeatable process. This gives you an idea of how accurate your estimation is for future projects and helps eliminate the possibility of mistakes in manual calculations.
Whether you use this spreadsheet or develop your own, by the second or third time you use it, you should be getting relatively accurate estimates for your particular system.
How to Extrapolate Your Results?
Once you’ve calculated the index and table sizes for the first year, add the total sizes together for all objects. This is a good working total for the first year’s growth, and you can double it to provide a two-year estimate.
Keep in mind that estimated sizes too large for a single file will require additional data files. Base your estimates on the constraints of the operating system or available space. Multiple data files may extend the size estimate for a particular tablespace.
SoftArt Solutions is an experienced Oracle consulting company that serves clients across the United States. Contact us with any questions you have on how to size an Oracle database or perform patching on your Oracle Database.
