Order of columns

Question

Does order of columns in table matter?

Answer 1

Hi ChaitanyaKiran-2787,

It may depend on what columns you have. It's all in the cost of the variable array's offset values. If the large majority of your NULLable records are at the end, then SQL Server doesn't need to completely populate the variable block array (which saves 2 bytes per column). If you have a table where 36 columns are NULLable and generally they are NULL, then defining those columns at the end of the row can save you space.
Please refer to Column order doesn’t matter… generally, but – IT DEPENDS and Does the order of columns in a table's definition matter which might be helpful.

Best Regards,
Amelia

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Answer 2

Not really. It should not matter. If you use ALTER TABLE command, the new column is added at the end.

Answer 3

If you ask me, it matters. More precisely, it matters to humans who work with the table. But it has no effect on performance, it that is what you are asking.

Answer 4

The order of columns doesn't matter from a technical point.

If you have any preference for the order, e.g. of better readable, create a view with a column order as you like.

Answer 5

Some articles mention that the physical order of the fields in a row does not correspond to the order that was specified in CREATE TABLE statement. Therefore, if it is true, the physical order of columns probably matters, but the order in CREATE TABLE does not matter.