Creating a clustered index on this heap?

Question

So I am curious to know if it is worth creating a clustered index on a heap table that has about 30M rows of data. Before now, it wasn't going to be used in any application that we have but now we are creating an app to query that table.

The reason why I ask if it is worth it is because the application we are creating is basically doing this type of query.

SELECT *
FROM [table];

I am leaving the * in to represent that we are basically pulling all fields.

So my question is, is it worth creating a clustered index on a table that does not have one even though we are going to be selecting all fields and rows for our application?

Thanks for any info/advice.

Answer 1

No it is not worth it. If you are going to run a select without a where clause, a clustered index will just add more data to the Page files, depending on what you choose for your index(It all really depends on your data). Creating a larger scan of the table. A Heap table is the actual better performance wise in many situations(if you are just getting all rows from a table and not using joins/wheres/filter clauses of some sort), because it is stored in less page files.

Having a clustered index, when it isnt used will also bear some overhead in updating/creating stats on a table and doing inserts (page splits)

So if you arent going to use the index, and aren't going to filter on your table you are better off without the index