If SET STATISTICS is done on one connection, when does it take effect?

What about a transaction that was already running at the time someone
else did SET STATISTICS, does that use the new statistics for any new
statements it runs (where all the code running is in stored procedures)?

What about a connection that was already in existence at the time
someone else did SET STATISTICS, does that use the new statistics for
any new transactions it runs (where all the code running is in stored
procedures)?

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Tim Ward