Will Changing the Max Memory Setting Invalidate Query Plans?

Question

I recently lowered the max memory from the default (unlimited) down to 20 GB. Does this erase the oldest queries in the plan cache?

Answer 1

Per Microsoft documentation changing the max server memory will clear the plan cache, as will changing:

• access check cache bucket count
• access check cache quota
• clr enabled
• cost threshold for parallelism
• cross db ownership chaining
• index create memory
• max degree of parallelism
• max server memory
• max text repl size
• max worker threads
• min memory per query
• min server memory
• query governor cost limit
• query wait
• remote query timeout
• user options