Estimating the Size of a SQL Table

Estimating the Size of a Table

The following steps can be used to estimate the amount of space required to store the data in a table:

  1. Specify the number of rows present in the table:

    Number of rows in the table = Num_Rows

  2. If there are fixed-length and variable-length columns in the table definition, calculate the space that each of these groups of columns occupies within the data row. The size of a column depends on the data type and length specification. For more information, see Data Types.

    Number of columns = Num_Cols

    Sum of bytes in all fixed-length columns = Fixed_Data_Size

    Number of variable-length columns = Num_Variable_Cols

    Maximum size of all variable-length columns = Max_Var_Size

  3. If there are fixed-length columns in the table, a portion of the row, known as the null bitmap, is reserved to manage column nullability. Calculate its size:

    Null Bitmap (Null_Bitmap) = 2 + (( Num_Cols + 7) / 8 )

    Only the integer portion of the above expression should be used; discard any remainder.

  4. If there are variable-length columns in the table, determine how much space is used to store the columns within the row:

    Total size of variable-length columns (Variable_Data_Size) = 2 + (Num_Variable_Cols x 2) + Max_Var_Size

    If there are no variable-length columns, set Variable_Data_Size to 0.

    This formula assumes that all variable-length columns are 100 percent full. If you anticipate that a lower percentage of the variable-length column storage space will be used, you can adjust the result by that percentage to yield a more accurate estimate of the overall table size.

  5. Calculate the row size:

    Total row size (Row_Size) = Fixed_Data_Size + Variable_Data_Size + Null_Bitmap +4

    The final value of 4 represents the data row header.

  6. Calculate the number of rows per page (8096 free bytes per page):

    Number of rows per page (Rows_Per_Page) = ( 8096 ) / (Row_Size + 2)

    Because rows do not span pages, the number of rows per page should be rounded down to the nearest whole row.

  7. If a clustered index is to be created on the table, calculate the number of reserved free rows per page, based on the fill factor specified. For more information, see Fill Factor. If no clustered index is to be created, specify Fill_Factor as 100.

    Number of free rows per page (Free_Rows_Per_Page) = 8096 x ((100 - Fill_Factor) / 100) / (Row_Size + 2)

    The fill factor used in the calculation is an integer value rather than a percentage.

    Because rows do not span pages, the number of rows per page should be rounded down to the nearest whole row. As the fill factor grows, more data will be stored on each page and there will be fewer pages.

  8. Calculate the number of pages required to store all the rows:

    Number of pages (Num_Pages) = Num_Rows / (Rows_Per_Page - Free_Rows_Per_Page)

    The number of pages estimated should be rounded up to the nearest whole page.

  9. Calculate the amount of space required to store the data in a table (8192 total bytes per page):

    Table size (bytes) = 8192 x Num_Pages

Umbraco custom section name - How to remove square brackets?

After configuring the custom section with help of IApplication interface in Umbraco, you must have faced issue with custom section name decorated with square brackets. This issue occurs due to the translations (language) being missing in config file for custom section name.

Problem - Remove square brackets from custom section name-

Soultion - Goto Umbraco\Config\Lang folder in your umbraco project

In en.xml file, under sections area - add key with alias magic and provide a relevant name as shown below-

Done square brackets are removed and replaced with custom description. Check out-

Hope this helps.

Installing Umbraco 7+ in visual studio 2012/2013

How to install Umbraco 7+ in visual studio 2012/13 using nuget package

1. Create a blank Web application using visual studio

2. Open package manager console. Select appropriate project(web application) and hit command 
Install-Package UmbracoCms -Version 7.2.6
At the time of writing this post Umbraco 7.2.6 was the latest version.

3. Done- Umbraco is installed. All binaries and config files are automatically included in project.

4. Run web application and Umbraco site setup details are asked.

Nullable type issue with ?: Conditional Operator

Consider if you want to use if and only if condition (IIF) with a nullable type
DateTime? foo;
foo = true ? null : new DateTime(0);
This will throw a compiler error. To resolve this cast null to nullable type as below-
foo = true ? (DateTime?)null : new DateTime(0);

List of LINQ syntax for immediate execution

This are some of the LINQ syntax for immediate query execution (more to add)-

1. ToList()
2. FirstOrDefault
3. Aggregate Methods (like Count(), Sum() etc.)
4. AsEnumerable()

As I said there are more to add, will keep updating as and when I find more methods.

Happy Coding!!!

Visual Studio - Solution Folder

To group .net projects in visual studio create Solution Folder 
Right Click Solution --> select Add option --> select New Solution Folder

Add a New or Existing Project-

Reference -

Adding Custom section in Umbraco 7+

To add a custom section in Umbraco add following class to your VS Umbraco Solution-
 public class Section : IApplication{}

Use following namespace-
using umbraco.businesslogic;
using umbraco.interfaces;
using Umbraco.Web.Mvc;

Refere following Umbraco dll's-
  • businesslogic.dll
  • intefaces.dll
  • umbraco.dll
Dont forget to provide admin user access to the newly added section

Screenshot below -

Please note the first time you run app after making this change Umbraco will update application.config file. So you might consider to close the application and run again to reflect the change.

application.config file is located in Config folder.

Unfortunately I am not able to remove square brackets [Magic] in custom section, as soon as I know it will share with you,

Also will shortly share how to configure Umbraco in VS2013.