[eluser]Pascal Kriete[/eluser]
You could download EE core and take a look

.
It actually doesn't store any results at all.
The pertinent stuff: the id (hash), keywords (what you searched for), search date (for pruning), total results (the count), and the query.
As well as a few more EE related things. You can probably piece together how it works from there. The stored query doesn't include the limit clause (for obvious reasons).