Estimating Your Space Needs

  • Comments posted to this topic are about the content posted at

    Kindest Regards,

    Andre Vigneau MCSE, MCDBA

  • Nice article.

    In all the articles that mention planning storage space I have never yet seen one that mentions archiving and removing obsolete data to conserve space.

    From my own experience I have seen a large number of databases where users insist that old data is needed and absolutely vital to the business but in reality it is almost never accessed.

    I have seen servers and infrastructure upgraded at vast cost to retain obsolete data.

  • I once saw some software that automated the functions of the excel spreadsheet in this article, but can't find it again.  Anyone familiar with it.

    I also need the same type of information for estimating server processor and memory requirements.  Anyone have a good reference?

  • When trying to run the DB script on a Database - I get an error

    "Server: Msg 8115, Level 16, State 2, Line 19

    Arithmetic overflow error converting expression to data type int."

    Any ideas why ?

    The line that Query Analyser jumps to is the start of the huge select statement.

    select DT1.TABLE_NAME






  • Haev a quick investigation - one of the tables has a datatype of image and is trying to sum the image size which is then greater than an int.

    This is for the section relating to the fixed data size.

    select CASE WHEN COLUMN_DATATYPE = 'int' then 4

    WHEN COLUMN_DATATYPE = 'bigint' then 8

    WHEN COLUMN_DATATYPE = 'smallint' then 2

    WHEN COLUMN_DATATYPE = 'tinyint' then 1  

    WHEN COLUMN_DATATYPE = 'datetime' then 8

    WHEN COLUMN_DATATYPE in ('ntext','text') then 16

    WHEN COLUMN_DATATYPE like 'var%' then 0

    else COLUMN_LENGTH end AS Fixed_Data_Size



    where TABLE_NAME not like 'dst_%'

    AND COLUMN_DATATYPE not LIKE 'n[c-b-v]%'

    Andre: For my purposes I can remove add something in the script to exclude image datatypes. So need to take this into account when runing the sample.



  • The query I posted does not treat image datatype. So if you have images stored in your database that is the message you will get.

    You can modify the query to treat image datatype as text or ntext datatypes by replacing in the query this


    by this


    And then it should run fine. Didn't see much image into databases lately my mistake. But the article is to give you all a starting point to begin gathering numbers to help you justify your storage needs. Some details could be missing ... like image datatype.

    Sorry about that I see how to have the script corrected.



    Kindest Regards,

    Andre Vigneau MCSE, MCDBA

  • Excellent timing! I am currently planning a move to a SAN environment and have been using the "best guess" model to plan the volumes. It's nice to finally be able to document my needs and I'm sure that this will also help my case when I submit my justification to the purchasing department.

    BTW: Suprisingly, my "best guess" was only 10GB over the calculated estimate: mine - 750GB, calculated 739.251GB.

    Artificial Intelligence stands no chance against Natural Stupidity.

  • Very impressive. This is not what we do in a lost after-noon, do we ?

    I consider myself as pretty proficient in T-SQL, but for me these procedures are too complicated. In spite of all the databases I have built the last few years (all based on quite a few non-obvious T-SQL stored procedures), I must confess that I do not understand how these procedures have been built up.

    So, I must trust Mr. Andre Vigneau for his professionality (no reason to doubt about it).

    By the way: in order to have the procedure run, I had to replace three times "('ntext', 'text')" with "('ntext', 'text', 'image')" in the final Stored Procedure.


  • How can I obtain a copy of the query & spreadsheet referenced in this article?


  • The link to Excel is broken, anyone knows what is the new link?

  • Good articles but script or query is not available.


  • The links have been changed to the Resources section at the bottom of the article.

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