<p>I'm trying to figure out how big a certain database would be (it hasn't been created yet). I know how many rows and what the tables will be. Is there a feature in Oracle that will tell me the size of such a theoretical database? Is there a known math formula I can use? I know there is a feature to determine the size of an existing database, but I want to know how big it will be before I create it. </p>

[{'answer_id': 11080, 'author': 'Community', 'author_id': -1, 'author_profile': 'https://Stackoverflow.com/users/-1', 'pm_score': 4, 'selected': True, 'text': '<p>you can from the size of the data types for the columns in a table. You can then get a rough estimate of the size of a row in that table.  then for 1 to n tables, then for 1 row in 1 table for x rows in x tables = estimate of the database for a given rowsize.</p>\n\n<p>Long handed I know but this is how i normally do this.</p>\n'}, {'answer_id': 11124, 'author': 'Eric Z Beard', 'author_id': 1219, 'author_profile': 'https://Stackoverflow.com/users/1219', 'pm_score': 3, 'selected': False, 'text': "<p>You might try prototyping your design - create an initial version of the database and write some scripts (or use a tool) to populate the tables with a reasonable amount of data.  Then you will know for sure how much space X rows takes up.  If it's too much, you can go back to the drawing board with your design.  I know you want a figure before creating the database, but you'll never be able to account for everything that's going on with the physical data files under the hood.</p>\n"}, {'answer_id': 11126, 'author': 'Stu', 'author_id': 414, 'author_profile': 'https://Stackoverflow.com/users/414', 'pm_score': 1, 'selected': False, 'text': '<p>To be accurate, this can get really complex. For example, this is how you do it on MS SQL Server:</p>\n\n<p><a href="http://msdn.microsoft.com/en-us/library/aa933068(SQL.80).aspx" rel="nofollow noreferrer">http://msdn.microsoft.com/en-us/library/aa933068(SQL.80).aspx</a></p>\n'}, {'answer_id': 11195, 'author': 'bpapa', 'author_id': 543, 'author_profile': 'https://Stackoverflow.com/users/543', 'pm_score': 0, 'selected': False, 'text': '<p>Having an exact size wasn\'t too important, so I went with littlegeek\'s method. I figured out what my tables and columns would be, and <a href="http://lbd.epfl.ch/f/teaching/courses/oracle8i/server.815/a68003/01_04blt.htm" rel="nofollow noreferrer">looked up the sizes of the data types</a>, then did some good \'ole multiplying.</p>\n'}, {'answer_id': 14007, 'author': 'bruceatk', 'author_id': 791, 'author_profile': 'https://Stackoverflow.com/users/791', 'pm_score': 1, 'selected': False, 'text': "<p>You also need to include indexes in your estimates.  I've seen systems where the indexes were as big as the data.  The only way I would trust the answer is to do prototyping like Eric Z Beard suggests.  Different datbase systems have different overhead, but they all have it.</p>\n"}]
['https://Stackoverflow.com/questions/11055', 'https://Stackoverflow.com', 'https://Stackoverflow.com/users/543/']