Question

I am optimizing a query and am worried that SQL Server is caching execution plans so want to wipe them.

How do I do this?

Answer 1

You should do this: DBCC FREEPROCCACHE;

I also do this DBCC DROPCLEANBUFFERS;

Use DBCC DROPCLEANBUFFERS to test queries with a cold buffer cache
without shutting down and restarting the server.

To drop clean buffers from the buffer pool, first use CHECKPOINT to
produce a cold buffer cache. This forces all dirty pages for the
current database to be written to disk and cleans the buffers. After
you do this, you can issue DBCC DROPCLEANBUFFERS command to remove all
buffers from the buffer pool.