This is no work of mine but I wanted to highlight it since it´s such a good thing to utilise when optimizing your database and queries.
SELECT SUBSTRING(qt.text, (qs.statement_start_offset/2)+1, ((CASE qs.statement_end_offset WHEN -1 THEN DATALENGTH(qt.text) ELSE qs.statement_end_offset END - qs.statement_start_offset)/2)+1), qs.execution_count, qs.total_logical_reads, qs.last_logical_reads, qs.min_logical_reads, qs.max_logical_reads, qs.total_elapsed_time, qs.last_elapsed_time, qs.min_elapsed_time, qs.max_elapsed_time, qs.last_execution_time, qs.creation_time, qp.query_plan FROM sys.dm_exec_query_stats qs CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) qt CROSS APPLY sys.dm_exec_query_plan(qs.plan_handle) qp WHERE qt.encrypted = 0 ORDER BY qs.total_logical_reads DESC
You get all recently executed queries (which in itself can be useful for a legacy database), the execution count and times aswell as the last query plan.
Something you need to pay attention to is that the timed values here, like total_elapsed_time, is saved in microseconds instead of the usual millisecond. This means that to get the average time you would need to:
SELECT (qs.total_elapsed_time / qs.execution.count) / 1000000