Is there an equivalent of "OPTION(RECOMPILE)" or "WITH RECOMPILE" for an entire connection?
Execution plans do not last for the duration of a connection: they are shared across all connections.

It has to be specified per query because any plan cache/reuse issues affect only that plan.

What are you trying to do please, and why do you think it would help?

Edit, after comment

The plan must exist in cache to be used (and reused). When it's cached, it uses memory. Recompiling would use the same memory and use extra CPU etc to recompile.

You said "tons of commands" and "thousands of databases": this is your problem. And probably no "dbo." etc to help plan reuse

Thoughts:


buy bigger server + more RAM
migrate to 64 bit with as much RAM as possible
split databases onto different servers
forced parameterisation
check quality of queries