Sorting by DATETIME slower than by TIMESTAMP?
You can shorten the running type of queries by indexing certain columns.

Since you mentioned sorting DATETIME fields, one of the best ways to bypass sorting of temp table results is to use a covering index which includes the DATETIME as the last column of any given compound index you need.

I know this is entirely possible because in a link about Covering Indexes By Ronald Bradford, he gave a list of future topics he was giving. Here is that list:


Some future topics on indexes not discussed here include:

Using UNIQUE Indexe
The impact of NULL columns and values on indexes
Eliminating filesort by using indexes &lt;&lt;&lt;---- (PLEASE NOTE THIS)
The affect of too many indexes
Index cardinality