Fill Factor Setting and Performance

Question

From what I've read, typically for indexing the recommendation is to leave the fill factor at 70-80, and the logic behind this seems that new data may be inserted into a table between existing values thus fill factor shouldn't be set as 100. In a hypothetical example of usernames, new names may be added to the name field, so a fill factor of 100 could create a problem because, even though the pages are full, the new data won't be organized appropriately with the other data.

My question involves a table where data are organized by date (clustered index) and ID (non clustered index); each order has a date and an ID thus no "new" orders can occur between existing orders and no new IDs can appear between existing IDs - these happen sequentially. For a table like this, would it be appropriate from a performance perspective to set the fill factor to 100 and reindex at 100, meaning are there performance advantages to having the pages full since no new data will appear between existing data?

Answer 1

Have you considered updates? If you change a row and the new data does not fit in the same space the row would have to be moved to a new page. If you can rule this out, filling the pages to 100 percent will reduce the space the table uses and consequentially give you a slight performance improvement.

Answer 2

The default fill factor is zero, which is identical to 100. As per the product documentation,

The fill-factor value is a percentage from 1 to 100, and the server-wide default is 0 which means that the leaf-level pages are filled to capacity.

Trying to find an opitmal value for fill factor is a well-researched problem. In the described scenario, there is not much to be done unless the table doesn't use default values.