Some days ago I discovered the Stack Exchange Data Explorer (SEDE) which provides already lots of interesting queries out of the box (thanks to the contributors).
After a while I noticed that some of the queries are running very long. In fact, they ran so long that they were cancelled by the system, which showed the following message:
Something unexpected went wrong while running your query. Don't worry, blame is already being assigned.
One example is the Top Users by Country list. Well, I thought this isn't really a big issue, because I can (try to) enhance the query myself. So I opened the query composer, saw the SQL text field on the left and the database schema on the right. A quick search returned some additional descriptions of the tables the columns.
But what I missed was a description of indexes and foreign keys, because they have a big influence on how I build a query and they are quite essential for query optimization.
So my questions: can I find this information somewhere? Or even better: could this be added to the SEDE? I'd appreciate it as well, if I could evaluate an execution plan without running the query. Would that be possible?
p.s.: as per comment here is an execution plan from the SEDE for the simple statement below:
SELECT ROW_NUMBER() OVER(ORDER BY Reputation DESC) AS [#], Id AS [User Link], Reputation FROM Users WHERE id = 1 ORDER BY Reputation DESC;
This information is very helpful for query optimization - in particular for more complex and long running statements.